Note it's 5 HS, 6 College with the extra pick.
But the answer is 2003. 4 in 2004, then Chadd took over drafts.
This isn't in a vaccuum, though. I'm guessing, and I could be wrong here, due to the covid years and NIL that college seniors have right now, college juniors are a bit less signable and high school players are a bit more crowded out, shifting the tide a bit.