| Castleton - Educational Attainment | FIPS Code=21015 |
| 1970 | 1980 | 1990 | |
| Per Cent of Individuals Ages 25 and Older without a High School Diploma | 44.58 | 31.00 | 14.10 |
| Per Cent of Individuals Ages 25 and Older with a High School Diploma or Equivalent | 31.71 | 30.50 | 33.30 |
| Per Cent of Individuals Ages 25 and Older with a Bachelor's Degree or Some College | 8.54 | 16.50 | 26.90 |
| Per Cent of Individuals Ages 25 and Older with a Doctorate, Professional or Master's Degree | 15.15 | 22.00 | 25.60 |