I'm not sure how important this is (i.e., whether it is worth the trouble), but you could reverse the sign of X in a separate data step, do ORDER=-34 to -2 by 2, and then include either a FORMAT that removes the negative sign or use VALUE= to specify how you want all of the values to be displayed.
2025 SAS Hackathon: There is still time!
Good news: We've extended SAS Hackathon registration until Sept. 12, so you still have time to be part of our biggest event yet – our five-year anniversary!