Groovy add column value in csv file

I need to export JSON in csv file. how to add values ​​to each column? I know how to add rows. Here's an example code:

def data = [
        ['place', 'firstname', 'lastname', 'team'],
        ['1', 'Lorena', 'Wiebes', 'Team DSM'],
        ['2', 'Marianne', 'Vos', 'Team Jumbo Visma'],
        ['3', 'Lotte', 'Kopecky', 'Team SD Worx']
]
def file = new File("C:/Temp/data.csv")
file.text = data*.join(',').join(System.lineSeparator())

Result:

I need result:

Please suggest good literature on Groovy with examples, thank you.

def data = [
        ['place', 'firstname', 'lastname', 'team'],
        ['1', 'Lorena', 'Wiebes', 'Team DSM'],
        ['2', 'Marianne', 'Vos', 'Team Jumbo Visma'],
        ['3', 'Lotte', 'Kopecky', 'Team SD Worx']
]
    def file = new File("C:/Temp/data.csv")

    def stringBuilder = new StringBuilder()
    data.each { row ->
    stringBuilder.append(row.join(';')).append(System.lineSeparator())
    }

    file.text = stringBuilder.toString()