I would even say it is a little higher than that...
for example the dome works very closely with HGSA (Hilliard rec softball program) who carries around 500 girls per year on average. If this is just one rec softball association, I am sure there are at least 30 if not more all around Ohio. Also, from a travel team perspective, we have 8 teams (just shy off 100 girls) and we are one of the smaller organizations in the area. Organizations such as the Lasers, Stingrays, Bandits, and even your Hawks, Doom, Classics and Pride teams are around the 15-20 teams per organization. That puts you around 250 kids per org in just those top ones I named.
I would guess to triple or quadruple the original number you mentioned!