The standards didn't change. What did change is that they went back to the old system with subcategories of high, medium, and low. You need to achieve at least probationary in all categories for the IST. The updated charts are here: http://www.public.navy.mil/bupers-npc/support/21st_Century_Sailor/physical/Documents/Guide 5- Physical Readiness Test 2016.pdf
Thanks Splonk!