U.S. IDEA Cases of Autism
| Age Group | 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 |
|---|---|---|---|---|---|---|---|---|
| 6-11 years | 2,896 | 8,769 | 10,981 | 13,538 | 17,477 | 21,469 | 27,154 | 34,938 |
| 12-17 years | 1,613 | 4,789 | 5,702 | 6,648 | 8,685 | 9,965 | 12,069 | 15,326 |
| 18-21 years | 585 | 1,744 | 2,013 | 2,145 | 2,563 | 2,574 | 2,914 | 3,380 |
| Total Autism | 5,094 | 15,302 | 18,696 | 22,331 | 28,725 | 34,008 | 42,137 | 53,664 |
| All disabilities | 4,464,761 | 4,592,790 | 4,736,029 | 4,866,540 | 5,036,139 | 5,185,444 | 5,347,058 | 5,486,630 |
| % with Autism | 0.11% | 0.33% | 0.39% | 0.46% | 0.57% | 0.66% | 0.79% | 0.98% |
| Total Retardation | 537,602 | 518,498 | 536,632 | 555,440 | 570,825 | 579,509 | 589,093 | 596,824 |
| % with Retardation | 12.04% | 11.29% | 11.33% | 11.41% | 11.33% | 11.18% | 11.02% | 10.88% |
| Age Group | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 |
| 6-11 years | 43,292 | 52,172 | 63,794 | 74,446 | 85,577 | 96,799 | 109,869 | |
| 12-17 years | 18,359 | 22,329 | 28,668 | 37,154 | 46,837 | 59,253 | 71,889 | |
| 18-21 years | 3,966 | 4,584 | 5,570 | 6,669 | 7,986 | 9,500 | 10,885 | |
| Total Autism | 65,617 | 79,085 | 98,032 | 118,269 | 140,400 | 165,552 | 192,643 | |
| All disabilities | 5,620,764 | 5,711,482 | 5,797,930 | 5,892,878 | 5,970,497 | 6,033,425 | 6,021,462 | |
| % with Autism | 1.17% | 1.38% | 1.69% | 2.01% | 2.35% | 2.74% | 3.20% | |
| Total Retardation | 600,457 | 599,738 | 592,657 | 580,656 | 571,124 | 555,524 | 533,426 | |
| % with Retardation | 10.68% | 10.50% | 10.22% | 9.85% | 9.57% | 9.21% | 8.86% | |
| Notes: Data from OSEP 2006IDEA Part B Data History, as reported by individual states in compliance with IDEA | ||||||||
Graphs of U.S. IDEA Autism Rates
U.S. IDEA 2005 Autism Rates for Selected States
| Autism Ages 6 to 21 (National Rate: 3.20% of IDEA Cases) | ||||||
|---|---|---|---|---|---|---|
| Calif. | Kent. | Minn. | Ohio | Texas | Wisc. | |
| Autism as % of State IDEA Cases | 4.36% | 2.06% | 7.23% | 3.12% | 3.13% | 3.97% |
| State as % of IDEA Students | 10.12% | 1.45% | 1.71% | 4.05% | 7.76% | 1.89% |
| State Autism as % of U.S. Cases | 13.81% | 0.93% | 3.87% | 3.94% | 7.58% | 2.35% |
| Estimated State Size as % of U.S. | 12.02% | 1.39% | 1.70% | 3.78% | 7.75% | 1.83% |
| Autism Ages 3 to 5 (National Rate: 4.32% of IDEA Cases) | ||||||
| Calif. | Kent. | Minn. | Ohio | Texas | Wisc. | |
| Autism as % of State IDEA Cases | 11.95% | 1.27% | 8.65% | 1.75% | 5.28% | 3.50% |
| State as % of IDEA Students | 9.54% | 3.05% | 1.92% | 3.25% | 5.76% | 2.30% |
| State Autism as % of U.S. Cases | 26.42% | 0.90% | 3.84% | 1.32% | 7.04% | 1.86% |
| Estimated State Size as % of U.S. | 12.02% | 1.39% | 1.70% | 3.78% | 7.75% | 1.83% |
The OSEP data for the six selected states reveal the following:
1) Minnesota classifies more than twice the normal rate of IDEA cases as autism in both age ranges analyzed by the U.S. Department of Education.
2) For ages 6 to 21, Minnesota reports twice the number of cases expected for the state population.
3) Both California and Minnesota show unusual spikes in the percentage of IDEA students classified as autism under the age of six for the year 2005. These states reported more than twice the number of autistic students as anticipated for their populations.
4) Kentucky and Ohio reported lower percentages of students as autistic than the national average.