If you had a number field in every record with the value 1 in every case a "fraction of total" summary field formatted to display as percent might work here if you set it to summarize that added number field.
Using what you currently have, you can set up 4 calculation fields that use the GetSummary function.
The expression for the fiscal year percentage would be
GetSummary ( YourSummaryFieldHere ; FiscalYearFieldHere ) / YourSummaryFIeldHere
No need to multiply by 100, you can just use data formatting in the inspector to format the field as a percent. in each calculation, you specify a different break field. The break field is the field you specified as the "sorted by" field for the corresponding sub summary layout part.
OK I will give that a try, Thanks.
I ended up adding the two fields (zccount = 1, and zsFaction) and after I remembered to format the field as percent with 1 decimal, it worked great!