Another thing about this statistic is the fact you can easily 'cheat' on it...
If you want to keep your putts down, use the 3wood to knock the ball in from very short distance, just inches for example.
I have seen guys doing this in matchplay rounds, tried it myself a few times now and it works... in other words, I think this stat should be calculated by the number of shots on the green rather than shots made with the putter...
I used to be proud of the rounds with 24 or less putts, but using this 'trick' anybody can quite easily achieve that...