| Keyword | CPC | PCC | Volume | Score | Length of keyword |
|---|---|---|---|---|---|
| prison numbers since 1970 | 0.9 | 0.7 | 4007 | 89 | 25 |
| prison | 0.63 | 0.4 | 7496 | 60 | 6 |
| numbers | 1.81 | 0.3 | 3237 | 28 | 7 |
| since | 0.61 | 0.1 | 4720 | 76 | 5 |
| 1970 | 1.88 | 0.6 | 1045 | 43 | 4 |
| Keyword | CPC | PCC | Volume | Score |
|---|---|---|---|---|
| prison numbers since 1970 | 1.08 | 1 | 2839 | 100 |
| prison population in 1970 | 0.59 | 0.1 | 5170 | 94 |
| prison population growth since 1970 | 0.81 | 1 | 8617 | 26 |
| us prison population increase since 1970 | 1.47 | 0.7 | 9492 | 87 |
| since 1980 the prison population has | 1.07 | 0.1 | 7912 | 47 |
| prison population in 1990 | 1.5 | 0.7 | 6530 | 24 |
| in the 1990s the prison population | 1.33 | 0.7 | 2775 | 74 |
| incarceration rates since 1970 | 0.42 | 0.6 | 230 | 61 |
| us prison population in 1980 | 1.47 | 0.7 | 3617 | 72 |
| prison population in 1993 uk | 1.02 | 0.6 | 7743 | 65 |
| how did prisons change in 1970 | 1.37 | 0.3 | 3493 | 86 |
| prison population by year | 1.06 | 0.8 | 5312 | 24 |
| prison population in 2000 | 0.51 | 0.7 | 37 | 16 |
| united states prison population by year | 1.54 | 0.6 | 8257 | 96 |
| united states prison statistics | 0.54 | 0.5 | 5649 | 94 |
