There are the MarkeTrac prevalence data that should give a good idea of what you're looking for.
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Ken W. Grant, PhD
Chief, Scientific and Clinical Studies
National Military Audiology and Speech-Pathology Center (NMASC)
Walter Reed National Military Medical Center
On Jan 26, 2016, at 9:48 AM, Jan Schnupp <jan.schnupp@xxxxxxxxxxxxx> wrote: