IMHO, if that is to be set up, wouldn't you need to (at least) divorce T1 from T2? Even if you didn't do that, I can't see what the average could possibly tell you as the numbers (in my short time on the board) range from small children to those in their 70s and beyond.
You can set up a poll. Go to the section you want,eg, Diabetes discussions ? click start new thread then scroll down and you should see poll options and a little more info and take it from there. Good luck, but any problems message Admin/Moderator
The info is already there, I checked 10 member's profiles at random, only 2 don't include their age, which of course is their prerogative, but might also mean that they wouldn't supply the details if asked. A lot of over 50s, but then just a small random sample.