The Census 2000 Brief on Disability Status includes estimates by state. According to those figures Indiana's total population is 5,563,619. Of that number, 19.0% (5 and older, non-institutionalized) experience some level of disability:
3.8% sensory
8.3% physical
4.8% intellectual
2.5% self care
Of people ages 16-64, 11.3% have an employment disability. Helpful statistical information can be found at: www.census.gov/census2000/states/in.html
The Stats Indiana Web site also has some helpful data and charts: www.stats.indiana.edu/