| Thetford - Property Tax Rates | FIPS Code=17055 |
| Year | Effective Tax Rate |
| 1970 | 1.41 |
| 1972 | 1.53 |
| 1974 | 1.41 |
| 1978 | 1.71 |
| Year | Effective Tax Rate | Municipal Tax Rate | School Tax Rate | |
| 1980 | 1.96 | 0.35 | 1.61 | |
| 1982 | 1.86 | 0.38 | 1.48 | |
| 1983 | 1.83 | Not Available | Not Available | |
| 1985 | 1.66 | Not Available | Not Available | |
| 1987 | 1.62 | Not Available | Not Available | |
| 1988 | 1.74 | 0.32 | 1.42 | |
| 1989 | 1.56 | 0.27 | 1.29 |
| Year | Effective Tax Rate | Municipal Tax Rate | School Tax Rate |
| 1990 | 1.58 | 0.27 | 1.31 |
| 1991 | 1.67 | 0.33 | 1.34 |
| 1993 | 1.87 | 0.36 | 1.51 |
| 1995 | 2.03 | 0.41 | 1.63 |
| 1997 | 2.17 | 0.41 | 1.76 |