Why would the RowCount attribute ever have a value other than "0" in your XSLT, as that is what you have hard coded it to be.
The following might do the trick, depending on context and various other things that aren't quite clear from the examples you've given).
Code:
<Section RowCount="{count(o:Response/o:Result/o:information[o:incrYear=$TaxYear])}">