This was 14 percent lower than the state average of 40.9 percent. In 2020 the total municipality population reached 542.
92 percent of the population had at least a high school diploma or the equivalent.
Degree distribution in Keystone for 2020*
| Degree | Number of people | Percentage of population | 
|---|---|---|
| No degree | 24 | 8 | 
| Regular high school diploma | 127 | 42.2 | 
| GED or alternative credential | 19 | 6.3 | 
| Some college, less than 1 year | 16 | 5.3 | 
| Some college, 1 or more years, no degree | 34 | 11.3 | 
| Associate's degree | 27 | 9 | 
| Bachelor's degree | 48 | 15.9 | 
| Master's degree | 3 | 1 | 
| Professional school degree | 1 | 0.3 | 
| Doctorate degree | 2 | 0.7 | 

              
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