In our (upper income, university town) school district, 25% of the kids test as gifted, defined as 96% or above on the OLSAT (or a test like the WISC, etc.).
That has been the argument as to why the school board has been trying to get rid of or at least limit our gifted program, which runs one grade level ahead. That "too many kids" are testing into it. that seems like such a silly argument.
We have at our high school about 30 NMF/commended scholars a year, quite a lot, and the high school offers 20 AP classes. Alot of IQ is linked to- the education level and income level of the family, so I am not surprised if alot of kids in our district hit the required metric.