Try the following PROC TABULATE code:
proc tabulate data=final;
class fyr admitsrc drg;
var pats;
table admitsrc*(drg all) ,fyr*(pats*sum pctn);
run;
If this does not answer your question, I would suggest opening a tracking number with Technical Support by sending email to support@sas.com with your code, a sample of the output, and an explanation of the percentages you are trying to get.