This was the cycle of the 2017-18 performance year. Performance works on an April 1 to March 31 year, give or take a bit of leeway at either end of the year.
As I think Ms. Sherman tried to explain, we always seek the input of ministers to provide a recommended rating. It's true that ministers don't set the pay, but they do provide input on the rating. The whole scheme is on the Internet, and you can see the criteria and the rankings and so on.