| Northfield - Population Change | FIPS Code=23065 |
| Absolute Population Change, 1970-1980 | 565 |
| Per Cent Population Change, 1970-1980 | 11.60 |
| Absolute Population Change, 1980-1990 | 175 |
| Per Cent Population Change, 1980-1990 | 3.22 |
| Population Estimate, 1996 | 5640 |
| Population Estimate, 2000 | 5580 |
| Population Estimate, 2005 | 5438 |
| Population Estimate, 2010 | 5310 |
| Population Estimate, 2015 | 5121 |
| Absolute Population Change, 1990-1996 | #REF! |
| Per Cent Population Change, 1990-1996 | 0.53 |
| Absolute Population Change, 1996-2005 | -202 |
| Per Cent Population Change, 1996-2005 | -3.58 |
| Absolute Population Change, 2005-2015 | -317 |
| Per Cent Population Change, 2005-2015 | -5.83 |