Bill, that of the not-qualified TT riders is a very interesting historical subject. How much are they? Who knows it!
And the introduction of the TT untimed practice sessions has done the things more complicated. Take the example of Thomas Montano this year and do not consider the fact that he already has a long TT career: he was out on the TT course during saturday untimed practices (and I think he completed at least one lap) but a road trafic accident on sunday put him out of the TT. The question is: has his participation to the 2007 TT practices been officially recorded?

So we can analyze the subject of the not qualified TT riders in this way:

1. riders who completed at least a TT course lap in a timed TT practice.
2. riders who did not complete a TT course lap in a timed TT pratice.
3. riders who run the TT course only in untimed TT practices (they can or can not have completed at least a TT course lap).

This could be a subject for a new TT book!