Oops! I'm embarassed to admit that my statistics are flawed. For some reason I was using 25 members per page when in fact it is 50 per page! That raises the number of members with post counts over 1024 from 57 to 132. And the number of who have posted in the last 4 months should be corrected from 34 to 109. The 23 posters with no activity in the last 4 months or more is still correct.
Sorry for the confusion. And thanx to the forum member who was kind enough to point out my stupidity with a PM!