My deer unit (3rd season) was in the 70's % success 2016, 80's % success 2017.
As far as elk (not sure if I'm going to buy an OTC tag or not), of 2 units I've been considering, I had just about ruled one out due to low 2016 harvest success. The other had 20-something % success. 2017 saw them flip-flop, the unit that had a good 2016 harvest had lower 2017 success, and vice-versa. I can definitely see the value of looking at 3-5 year trends due to weather fluctuations, sampling error, etc.