Gazoo,
I agree with your assessment as the bar is now in the 210 area. In my league that I've bowled in the last 5 years that would seem to be the case.
the 2000-01 season there were 3 or 4 bowlers over the 200 mark when we had 22 teams, last year we had 3 bowlers over 210 with 16 teams. So, that bar is a little better than the top 10%.
I think the problem comes in the next group, the people who are now in the 190-210 average group. 5 years ago, that group was 180-200, there were approx. 25 in that group out of 88 bowlers, about 30%, last year out of the 64 bowlers in league, in the 190-210 range, I would estimate that there were 30 in that group or about 40 or 45%.
This is the biggest reason you see the better bowlers complaining about the new tech in the balls. Today, you really don't need the physical ability to create optimum entry angles to carry strikes consistently. Five years ago I carried 172 ave. while my accuracy has improved some, this last summer league I finished at 193, I don't believe that I am 2 strikes better per game than I was 5 years ago, but with the newer balls that I am using, I will get those 2 extra strikes per game.