Refereeing frequency, redux

Last week's thread on frequency of refereeing and the subsequent poll generaetd more than 500 responses; here are the results:

How many journal articles do you referee in a typical year?   Selection   Votes  none  2% 12  1-6  48% 261  7-12  31% 171  13-24  15% 81  25-50  3% 18  50 or more  1% 5  548 total

If these results are representative, then it's clear a minority of referees are refereeing a majority of the papers.  Thoughts from readers?