How to find PGA used for each pl/sql statment?

We have a session that is using 190Mb of PGA:  

SID USERNAME PROGRAM LOGON_TIME MACHINE PGA_ALLOC_MB
---------- -------- ------------------------- --------------- ------------------------- ------------
497 LIMARES ResourcePlannerServer.exe 17-JUN 13:59:40 MAG\MA-APPS-095 187.75

We have extracted the SQL statements this session has ran over the past 24 hours, but we can't get the PGA used for each statement, so we can tune it.

Question: How do we get the PGA used for each SQL statement?

Thanks. Rgds. Sheryl