Data come from the IDEA Data System, U.S. Department of Education, Office of Special Education. Data are based on student counts as defined in the numerator and Denominator sections above. Data are aggregated by states and territories so that there are a total of 57 entries (50 states plus DC, Puerto Rico, Guam, American Samoa, Virgin Islands, N. Marianas, BIA). Thus specific population or demographic data are unavailable (i.e. data by gender, race-ethnicity).