What about school aged children?   

In the 1999-2000 school year, one study recorded 43,861 deaf and hard of hearing students who were identified for services in U. S. schools.   33.2% of these students were reported to be profoundly deaf.  Of the 43,861 students, 70% of these students do not regularly sign with their family members at home.  For more information on these statistics refer to
Gallaudet University's work.