The thing I found noticeable was that for about 5 years England were picking the odd player who was younger than me, but as late as 2001 (Lord's Test v Aus) 10 of the side was still older than me (all but Trescothick); then in the next few years a whole generation of England players slightly older than me (Atherton, Stewart, Butcher, Hick, Hussain, Thorpe, Ramprakash, Cork, Gough, Caddick, Tufnell etc) dropped out of the side, to be replaced by Trescothick, Strauss, Vaughan, Pietersen, Bell, Flintoff, Hoggard, Harmison, Anderson etc.
Just 3 years after that Lord's Test, there was an England side with 10 players younger than me (Oval 2004: all but Giles), and after that there were just a few more picks for Butcher and Thorpe, a surprising debut and handful of Tests for Udal, and a couple more years of Giles. I suspect this was a quicker swing from "mostly older" to "mostly younger" than most people get.