| Johnson - Educational Attainment | FIPS Code=15030 |
| 1970 | 1980 | 1990 | |
| Per Cent of Individuals Ages 25 and Older without a High School Diploma | 51.00 | 28.20 | 22.20 |
| Per Cent of Individuals Ages 25 and Older with a High School Diploma or Equivalent | 27.71 | 33.50 | 33.40 |
| Per Cent of Individuals Ages 25 and Older with a Bachelor's Degree or Some College | 12.18 | 16.20 | 23.50 |
| Per Cent of Individuals Ages 25 and Older with a Doctorate, Professional or Master's Degree | 9.10 | 22.20 | 21.00 |