| Statistics | 2010 | 2005 | 2015 | |||||||
| Census Data | Violations | TTHM | Violations | TTHM | ||||||
| Population | Income | Systems | Total | TTHM | [ppb] | Total | TTHM | [ppb] | % Change | |
| Mean (M) | 5,534,273 | $51,988 | 1882.1 | 2677.6 | 39.8 | 25.3 | 2893.1 | 27.8 | 62.5 | +156.1% |
| Standard Error | 2.7E+6 | 2049.2 | 562.4 | 775.3 | 17.1 | 2.0 | 546.1 | 9.7 | 3.5 | 16.3 |
| Variance | 9.5E+13 | 5.5E+7 | 4.1E+6 | 7.8E+6 | 3513 | 47.9 | 3.9E+6 | 1139 | 148.1 | 3182.6 |
| Standard Deviation (SD) | 9.8E+6 | 7388.5 | 2027.9 | 2795.4 | 56.4 | 6.9 | 1968.7 | 33.8 | 12.2 | 56.4 |