Well you did 3 more reps in the same number of sets in the same amount of time. That’s a 14% improvement in rep count, which is great. But keep in mind that you shouldn’t expect gains like this continuously, some days you will not feel as strong as on other days, but notice that you see fairly consistent improvement over time.
Here are a couple of slightly different approaches:
Try ascending ladders. Start at 1 rep, add a rep every set with fairly short rest periods between each set (personally I did maybe 10-30 seconds). Once you get to a high enough set that you can cleanly finish and maybe have one set left, restart at 1 and go back up. I would descend my max rep set by 1 every round. For example 18.104.22.168.22.214.171.124.126.96.36.199.1.2.1. Then after the last set maybe do a set to failure.
Pick a number near your max, in your case I’d say 8. Start busting out sets of 8. Once you can no longer finish, do negatives for the remainder of the set. So say your first 3 sets are 8 each, but the next set you only get 5, so immediately do 3 negatives.