The official State statistics are produced by the U.S. Department of Education, providing the number of disabled students ages 6-21 served by IDEA (Individuals With Disabilities Education Act) who have autism.
The data is in table format and compares the increase of students with autism over a period of 12 years (1992-93 and 2003-04).
U.S. DOE data available at:
http://www.ideadata.org/tables27th/ar_aa3.htm
For more information and resources on autism, go to: http://www.autismconcepts.com/.