It's always fun to take a walk down memory lane.

I notice that you are using the SG graphics, which are now part of Base SAS (not SAS/GRAPH). Starting with SAS 9.2, you can create a butterfly chart by using only PROC SGPLOT: no GTL required. You do have to manipulate the data a little. See http://blogs.sas.com/content/iml/2010/09/28/comparing-cell-phone-use-by-age.html