TRhit, great info for sure.
My son does speed training and works with someone who has a serious resume as it pertains to his expertise. He has trained athletes in all sports and all ages for many years and has a great reputation. Personally, I think he is fantastic and couldn't be happier with the results he has helped my son produce.
That being said, I asked him specifically about his opinion of the percentage of kids (High School in this case) who actually run sub 7 second 60's and if memory serves me correctly, his answer was well less than 10%.
Does that sound right to you?