Count Aggregate in FetchXML report

Trying to create a FetchXML report for CRM 2016 using VS2012 following instructions here: Create a new report using SQL Server Data Tools. I want to simply find a count of cases created between two dates.

The instructions talk about copy/pasting downloaded FetchXML from the CRM Advanced find process.

FetchXML generated by the Advanced Find process to list all Cases (by ticketnumber):

<fetch version="1.0" output-format="xml-platform" mapping="logical" distinct="false">
  <entity name="incident">
    <attribute name="incidentid" />
    <attribute name="ticketnumber" />
    <order attribute="ticketnumber" descending="false" />
    <filter type="and">
      <filter type="and">
        <condition attribute="createdon" operator="on-or-after" value="2015-07-01" />
        <condition attribute="createdon" operator="on-or-before" value="2016-06-30" />
      </filter>
    </filter>
  </entity>
</fetch>

I can't find a way to aggregate with Advanced Find, but instructions here: Use FetchXML aggregation seem to indicate a couple of attribute changes to the XML is all that is necessary.

So, I changed my FetchXML in notepad++ to:

<fetch version="1.0" output-format="xml-platform" mapping="logical" distinct="false" aggregate="true" >
      <entity name="incident">
        <attribute name="incidentid" />
        <attribute name="ticketnumber" aggregate="count" alias="casecount" />
        <order attribute="ticketnumber" descending="false" />
        <filter type="and">
          <filter type="and">
            <condition attribute="createdon" operator="on-or-after" value="2015-07-01" />
            <condition attribute="createdon" operator="on-or-before" value="2016-06-30" />
          </filter>
        </filter>
      </entity>
    </fetch>

This results in an error:

Either I'm doing something wrong, or that FetchXML Aggregation page is incorrect.

Can someone show me how to create a fetchXML report that counts cases opened between two dates?

You cannot select an attribute (incidentid) while at the same time doing aggregation.

Additionally, applying ordering does not make sense when you are aggregating.

I have removed those two lines, after which the FetchXML is able to run:

<fetch version="1.0" output-format="xml-platform" mapping="logical" distinct="false" aggregate="true" >
  <entity name="incident">
    <attribute name="ticketnumber" aggregate="count" alias="casecount" />
    <filter type="and">
      <filter type="and">
        <condition attribute="createdon" operator="on-or-after" value="2015-07-01" />
        <condition attribute="createdon" operator="on-or-before" value="2016-06-30" />
      </filter>
    </filter>
  </entity>
</fetch>

As a side-note, you might want to use the FetchXml Tester in XrmToolBox for quickly being able to edit and execute FetchXML.