EDT: Why Aren't YOU Doing It?

Quick question to revive this thread. Once you increase reps by 20%, and you add 5% to your weight, how many reps should you use for your new weight to continue your progression? Example: 200 pounds is your exercise 12 rep max and your first round you are able to do 40 total reps in 15 minutes. After two more rounds you are able to perform a total of 48 reps - a 20% increase. The next round you up the weight 5% to 210 pounds. Should you shoot for 40 total reps? Does it matter?