| Westfield - Population Change | FIPS Code=19090 |
| Absolute Population Change, 1970-1980 | 43 |
| Per Cent Population Change, 1970-1980 | 11.47 |
| Absolute Population Change, 1980-1990 | 4 |
| Per Cent Population Change, 1980-1990 | 0.96 |
| Population Estimate, 1996 | 464 |
| Population Estimate, 2000 | 407 |
| Population Estimate, 2005 | 395 |
| Population Estimate, 2010 | 381 |
| Population Estimate, 2015 | 368 |
| Absolute Population Change, 1990-1996 | 42 |
| Per Cent Population Change, 1990-1996 | 9.95 |
| Absolute Population Change, 1996-2005 | -69 |
| Per Cent Population Change, 1996-2005 |
| Absolute Population Change, 2005-2015 | -27 |
| Per Cent Population Change, 2005-2015 | -6.84 |