Stuck! Current query is by Supplier, Year-Month Percent Acceptance for that Month. Need to Add Column with 12 Month Rolling Average. Results needed:
Supplier mm-yy Avg 12_Mo_Avg
abc Feb-03 100.00% 100.00%
abc Mar-03 98.50% 99.25%
abc Mar-03 96.80% 98.40%
abc Apr-03 100.00% 98.80%
abc May-03...