Also, to run an analysis only on those three years you don't need to create a new dataset. You can simply use a WHERE statement when running the procedure. For example:
proc means data=have;
where year(DT_OPER) in (2010, 2011, 2012);
var myVar;
....
run;
PG
Available on demand!
Missed SAS Innovate Las Vegas? Watch all the action for free! View the keynotes, general sessions and 22 breakouts on demand.