I would be wary of using percentages in calculating your numbers. It isn't always clear cut. But if we assume that the 10% rule does hold true for you, then we could come to the reasonable conclusion that you did not stimulate any additional adaptation from switching to 3 sets of 3. This can either be because you didn't recover or the stress was insufficient to drive another adaptation. Many SSCs will tell you that reducing the volume is not what you need on the pressing movements when you are getting towards the end of your LP. Additional volume tends to drive progress in this situation.