Vega lite api miss-behaving

data = [{"student_name": "student 0", "e": "100.15", "d": "127.81"}, {"student_name": "student 1", "e": "100.30", "d": "189.94"}, {"student_name": "student 2", "e": "100.15", "d": "105.33"}, {"student_name": "student 3", "e": "99.41", "d": "85.36"}, {"student_name": "student 4", "e": "100.00", "d": "203.70"}, {"student_name": "student 5", "e": "100.15", "d": "139.05"}, {"student_name": "student 6", "e": "41.72", "d": "41.72"}, {"student_name": "student 7", "e": "100.30", "d": "260.50"}, {"student_name": "student 8", "e": "92.60", "d": "94.53"}, {"student_name": "student 9", "e": "99.11", "d": "86.39"}, {"student_name": "student 10", "e": "97.49", "d": "92.46"}, {"student_name": "student 11", "e": "98.37", "d": "83.58"}, {"student_name": "student 12", "e": "100.15", "d": "182.40"}, {"student_name": "student 13", "e": "100.15", "d": "99.41"}, {"student_name": "student 14", "e": "86.69", "d": "81.95"}, {"student_name": "student 15", "e": "98.08", "d": "306.51"}, {"student_name": "student 16", "e": "100.15", "d": "86.54"}, {"student_name": "student 17", "e": "100.15", "d": "186.39"}, {"student_name": "student 18", "e": "99.26", "d": "93.64"}, {"student_name": "student 19", "e": "100.15", "d": "102.66"}, {"student_name": "student 20", "e": "95.71", "d": "52.96"}, {"student_name": "student 21", "e": "99.85", "d": "99.41"}, {"student_name": "student 22", "e": "98.96", "d": "100.44"}, {"student_name": "student 23", "e": "100.15", "d": "131.07"}, {"student_name": "student 24", "e": "99.56", "d": "76.92"}, {"student_name": "student 25", "e": "100.15", "d": "213.46"}, {"student_name": "student 26", "e": "100.15", "d": "311.24"}, {"student_name": "student 27", "e": "100.15", "d": "21.89"}, {"student_name": "student 28", "e": "96.60", "d": "6.36"}, {"student_name": "student 29", "e": "53.70", "d": "3.70"}, {"student_name": "student 30", "e": "96.75", "d": "46.60"}, {"student_name": "student 31", "e": "100.15", "d": "100.15"}, {"student_name": "student 32", "e": "100.30", "d": "115.68"}, {"student_name": "student 33", "e": "87.13", "d": "103.85"}, {"student_name": "student 34", "e": "100.15", "d": "104.14"}, {"student_name": "student 35", "e": "99.26", "d": "59.17"}, {"student_name": "student 36", "e": "100.15", "d": "171.30"}, {"student_name": "student 37", "e": "99.11", "d": "94.08"}, {"student_name": "student 38", "e": "81.66", "d": "57.40"}, {"student_name": "student 39", "e": "96.01", "d": "154.59"}, {"student_name": "student 40", "e": "98.96", "d": "79.29"}, {"student_name": "student 41", "e": "99.26", "d": "118.20"}, {"student_name": "student 42", "e": "100.15", "d": "130.92"}, {"student_name": "student 43", "e": "90.53", "d": "47.63"}, {"student_name": "student 44", "e": "100.15", "d": "146.75"}, {"student_name": "student 45", "e": "96.01", "d": "197.63"}, {"student_name": "student 46", "e": "100.15", "d": "100.15"}, {"student_name": "student 47", "e": "107.25", "d": "115.24"}, {"student_name": "student 48", "e": "98.67", "d": "48.37"}, {"student_name": "student 49", "e": "88.61", "d": "190.53"}, {"student_name": "student 50", "e": "100.30", "d": "104.44"}, {"student_name": "student 51", "e": "51.18", "d": "51.18"}, {"student_name": "student 52", "e": "93.64", "d": "19.08"}, {"student_name": "student 53", "e": "100.00", "d": "123.08"}, {"student_name": "student 54", "e": "98.67", "d": "103.25"}, {"student_name": "student 55", "e": "98.37", "d": "95.86"}, {"student_name": "student 56", "e": "100.30", "d": "129.44"}, {"student_name": "student 57", "e": "100.15", "d": "164.50"}, {"student_name": "student 58", "e": "100.15", "d": "340.24"}, {"student_name": "student 59", "e": "100.30", "d": "165.83"}, {"student_name": "student 60", "e": "100.15", "d": "203.99"}, {"student_name": "student 61", "e": "92.75", "d": "160.06"}, {"student_name": "student 62", "e": "99.26", "d": "58.28"}, {"student_name": "student 63", "e": "99.41", "d": "99.41"}, {"student_name": "student 64", "e": "50.30", "d": "50.30"}, {"student_name": "student 65", "e": "93.79", "d": "50.30"}, {"student_name": "student 66", "e": "100.15", "d": "178.40"}, {"student_name": "student 67", "e": "99.11", "d": "6.21"}, {"student_name": "student 68", "e": "100.15", "d": "211.09"}, {"student_name": "student 69", "e": "100.15", "d": "69.08"}, {"student_name": "student 70", "e": "97.63", "d": "110.50"}, {"student_name": "student 71", "e": "100.15", "d": "126.33"}, {"student_name": "student 72", "e": "97.34", "d": "78.85"}, {"student_name": "student 73", "e": "100.15", "d": "182.99"}, {"student_name": "student 74", "e": "97.34", "d": "53.99"}, {"student_name": "student 75", "e": "98.22", "d": "45.12"}, {"student_name": "student 76", "e": "100.00", "d": "136.69"}, {"student_name": "student 77", "e": "98.82", "d": "41.72"}, {"student_name": "student 78", "e": "96.89", "d": "77.37"}, {"student_name": "student 79", "e": "97.78", "d": "81.36"}, {"student_name": "student 80", "e": "98.96", "d": "146.30"}, {"student_name": "student 81", "e": "99.26", "d": "48.67"}, {"student_name": "student 82", "e": "100.30", "d": "205.33"}, {"student_name": "student 83", "e": "98.82", "d": "141.42"}, {"student_name": "student 84", "e": "97.78", "d": "128.99"}, {"student_name": "student 85", "e": "100.15", "d": "86.69"}, {"student_name": "student 86", "e": "95.86", "d": "121.15"}, {"student_name": "student 87", "e": "97.49", "d": "88.31"}, {"student_name": "student 88", "e": "55.77", "d": "56.80"}, {"student_name": "student 89", "e": "96.01", "d": "13.17"}, {"student_name": "student 90", "e": "1.04", "d": "1.33"}, {"student_name": "student 91", "e": "99.70", "d": "26.18"}, {"student_name": "student 92", "e": "96.30", "d": "78.11"}, {"student_name": "student 93", "e": "99.85", "d": "11.83"}, {"student_name": "student 94", "e": "100.15", "d": "172.93"}, {"student_name": "student 95", "e": "100.00", "d": "198.82"}, {"student_name": "student 96", "e": "100.15", "d": "155.92"}, {"student_name": "student 97", "e": "92.01", "d": "97.19"}, {"student_name": "student 98", "e": "98.52", "d": "71.30"}, {"student_name": "student 99", "e": "100.15", "d": "111.69"}, {"student_name": "student 100", "e": "0.30", "d": "0.30"}, {"student_name": "student 101", "e": "91.72", "d": "86.54"}, {"student_name": "student 102", "e": "99.11", "d": "113.76"}, {"student_name": "student 103", "e": "98.22", "d": "67.75"}, {"student_name": "student 104", "e": "95.86", "d": "124.56"}, {"student_name": "student 105", "e": "105.92", "d": "201.48"}, {"student_name": "student 106", "e": "66.72", "d": "69.23"}, {"student_name": "student 107", "e": "100.15", "d": "151.18"}, {"student_name": "student 108", "e": "98.96", "d": "46.15"}, {"student_name": "student 109", "e": "100.15", "d": "160.36"}, {"student_name": "student 110", "e": "98.82", "d": "69.67"}, {"student_name": "student 111", "e": "98.08", "d": "80.03"}, {"student_name": "student 112", "e": "97.63", "d": "45.27"}, {"student_name": "student 113", "e": "96.60", "d": "37.28"}, {"student_name": "student 114", "e": "100.15", "d": "285.06"}, {"student_name": "student 115", "e": "98.96", "d": "77.81"}, {"student_name": "student 116", "e": "100.15", "d": "104.14"}, {"student_name": "student 117", "e": "100.15", "d": "160.65"}, {"student_name": "student 118", "e": "80.47", "d": "80.47"}, {"student_name": "student 119", "e": "100.15", "d": "115.09"}, {"student_name": "student 120", "e": "50.44", "d": "50.44"}, {"student_name": "student 121", "e": "100.15", "d": "136.83"}, {"student_name": "student 122", "e": "93.34", "d": "53.99"}, {"student_name": "student 123", "e": "100.15", "d": "136.09"}, {"student_name": "student 124", "e": "100.15", "d": "126.78"}, {"student_name": "student 125", "e": "89.35", "d": "74.85"}, {"student_name": "student 126", "e": "100.15", "d": "113.17"}, {"student_name": "student 127", "e": "97.78", "d": "78.25"}, {"student_name": "student 128", "e": "94.67", "d": "28.25"}, {"student_name": "student 129", "e": "100.15", "d": "154.88"}, {"student_name": "student 130", "e": "80.47", "d": "101.78"}, {"student_name": "student 131", "e": "99.11", "d": "66.42"}, {"student_name": "student 132", "e": "103.40", "d": "260.50"}, {"student_name": "student 133", "e": "99.11", "d": "17.75"}, {"student_name": "student 134", "e": "86.98", "d": "89.94"}, {"student_name": "student 135", "e": "96.30", "d": "81.66"}, {"student_name": "student 136", "e": "100.15", "d": "60.36"}, {"student_name": "student 137", "e": "100.15", "d": "73.52"}, {"student_name": "student 138", "e": "96.45", "d": "68.93"}, {"student_name": "student 139", "e": "100.30", "d": "165.83"}, {"student_name": "student 140", "e": "96.89", "d": "55.77"}, {"student_name": "student 141", "e": "100.15", "d": "112.72"}, {"student_name": "student 142", "e": "99.26", "d": "204.88"}, {"student_name": "student 143", "e": "100.15", "d": "356.51"}, {"student_name": "student 144", "e": "99.70", "d": "152.66"}, {"student_name": "student 145", "e": "100.15", "d": "40.83"}, {"student_name": "student 146", "e": "92.16", "d": "63.46"}, {"student_name": "student 147", "e": "100.15", "d": "179.88"}, {"student_name": "student 148", "e": "100.00", "d": "81.36"}, {"student_name": "student 149", "e": "16.57", "d": "11.98"}, {"student_name": "student 150", "e": "84.62", "d": "73.08"}, {"student_name": "student 151", "e": "100.59", "d": "100.59"}, {"student_name": "student 152", "e": "98.82", "d": "104.88"}, {"student_name": "student 153", "e": "99.11", "d": "135.95"}, {"student_name": "student 154", "e": "97.93", "d": "35.95"}, {"student_name": "student 155", "e": "100.15", "d": "101.92"}, {"student_name": "student 156", "e": "100.30", "d": "120.86"}, {"student_name": "student 157", "e": "81.07", "d": "88.76"}, {"student_name": "student 158", "e": "100.15", "d": "128.40"}, {"student_name": "student 159", "e": "94.67", "d": "119.23"}, {"student_name": "student 160", "e": "100.30", "d": "253.85"}, {"student_name": "student 161", "e": "91.42", "d": "68.05"}, {"student_name": "student 162", "e": "100.15", "d": "118.79"}, {"student_name": "student 163", "e": "100.15", "d": "101.04"}, {"student_name": "student 164", "e": "100.30", "d": "203.11"}, {"student_name": "student 165", "e": "100.59", "d": "155.18"}, {"student_name": "student 166", "e": "96.89", "d": "84.76"}, {"student_name": "student 167", "e": "100.15", "d": "115.38"}, {"student_name": "student 168", "e": "100.00", "d": "179.73"}, {"student_name": "student 169", "e": "100.15", "d": "135.65"}, {"student_name": "student 170", "e": "98.37", "d": "93.34"}, {"student_name": "student 171", "e": "100.15", "d": "128.40"}, {"student_name": "student 172", "e": "100.44", "d": "164.05"}, {"student_name": "student 173", "e": "98.37", "d": "57.54"}, {"student_name": "student 174", "e": "96.75", "d": "118.05"}, {"student_name": "student 175", "e": "98.96", "d": "91.12"}, {"student_name": "student 176", "e": "100.00", "d": "226.04"}, {"student_name": "student 177", "e": "98.67", "d": "150.89"}, {"student_name": "student 178", "e": "97.49", "d": "68.79"}, {"student_name": "student 179", "e": "100.15", "d": "133.58"}, {"student_name": "student 180", "e": 0, "d": 0}, {"student_name": "student 181", "e": 0, "d": 0}, {"student_name": "student 182", "e": 0, "d": 0}, {"student_name": "student 183", "e": 0, "d": 0}, {"student_name": "student 184", "e": 0, "d": 0}, {"student_name": "student 185", "e": 0, "d": 0}, {"student_name": "student 186", "e": 0, "d": 0}, {"student_name": "student 187", "e": 0, "d": 0}, {"student_name": "student 188", "e": 0, "d": 0}, {"student_name": "student 189", "e": 0, "d": 0}, {"student_name": "student 190", "e": 0, "d": 0}, {"student_name": "student 191", "e": 0, "d": 0}, {"student_name": "student 192", "e": 0, "d": 0}, {"student_name": "student 193", "e": 0, "d": 0}, {"student_name": "student 194", "e": 0, "d": 0}, {"student_name": "student 195", "e": 0, "d": 0}, {"student_name": "student 196", "e": 0, "d": 0}, {"student_name": "student 197", "e": 0, "d": 0}, {"student_name": "student 198", "e": 0, "d": 0}, {"student_name": "student 199", "e": 0, "d": 0}, {"student_name": "student 200", "e": 0, "d": 0}, {"student_name": "student 201", "e": 0, "d": 0}, {"student_name": "student 202", "e": 0, "d": 0}, {"student_name": "student 203", "e": 0, "d": 0}, {"student_name": "student 204", "e": 0, "d": 0}, {"student_name": "student 205", "e": 0, "d": 0}, {"student_name": "student 206", "e": 0, "d": 0}, {"student_name": "student 207", "e": 0, "d": 0}, {"student_name": "student 208", "e": 0, "d": 0}, {"student_name": "student 209", "e": 0, "d": 0}, {"student_name": "student 210", "e": 0, "d": 0}, {"student_name": "student 211", "e": 0, "d": 0}]

createChart = function (data) {
  max_d = d3.max(data, record => parseFloat(record.d));
  max_e = d3.max(data, record => parseFloat(record.e));
  max_y_scale_value_for_d = d3.max([100, max_d]);
  max_y_scale_value_for_e = d3.max([100, max_e]);

  const mpg = vl.markLine()
              .data(data)
              .transform([{ "calculate": "toNumber(datum.d)", "as": "d2" }, { "calculate": "toNumber(datum.e)", "as": "e2" }])
              
              .encode(
                      vl.x()
                        .fieldN('student_name')
                        .title('students')
                        .axis({ labels: false, ticks: false })
                        .sort('-y'),
                      vl.y()
                        .fieldQ('d2')
                        .scale({ "domain": [0, max_y_scale_value_for_d] })
                        .title('D'),        
                      vl.tooltip([{ 'field': 'student_name', 'title': 'Sudent Name' },
                                  { 'field': 'd', 'title': 'D' },
                                  { 'field': 'e', 'title': 'E' }])
                                ).width(500).height(250);

  const hp = mpg.markLine({ color: '#227a15' })     
              .encode(
                      vl.y()
                        .fieldQ('e2')
                        .scale({ "domain": [0, max_y_scale_value_for_e] })
                        .title('E')
                     );

  const plot = vl.vconcat(
                       vl.layer(mpg, mpg.markCircle()),
                       vl.layer(hp, hp.markCircle({ color: '#227a15' }))
                     )

  return plot.toObject();
}

const chart_spec_json = this.createChart(data)
const opt = {
               renderer: "canvas",
               actions: false
            };
vegaEmbed("#stats", chart_spec_json, opt);

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.13.0/d3.min.js"></script>
<script src="https://unpkg.com/vega@5.21.0/build/vega.min.js"></script>
<script src="https://unpkg.com/vega-lite@5.2.0/build/vega-lite.min.js"></script>
<script src="https://www.unpkg.com/vega-embed@6.20.8/build/vega-embed.min.js"></script>
<script src="https://unpkg.com/vega-lite-api@5.0.0/build/vega-lite-api.min.js"></script>
<div id="stats" />