Air pollution statistics for Suffolk Co, Massachusetts
3. Select a year
| Year | Percentage days with good air | Percentage days with moderate air | Percentage days with unhealthy air for sensitive groups | Percentage days with unhealthy air |
| 1997 | 93.97% | 5.48% | 0.55% | 0.00% |
| 1998 | 92.33% | 6.58% | 1.10% | 0.00% |
| 1999 | 73.97% | 23.84% | 2.19% | 0.00% |
| 2000 | 58.47% | 41.53% | 0.00% | 0.00% |
| 2001 | 56.44% | 40.55% | 2.47% | 0.55% |
| 2002 | 64.11% | 31.23% | 3.56% | 1.10% |
| 2003 | 55.34% | 42.47% | 1.92% | 0.27% |
| 2004 | 57.92% | 41.53% | 0.55% | 0.00% |
| 2005 | 59.45% | 37.81% | 2.47% | 0.27% |
| 2006 | 67.12% | 31.78% | 1.10% | 0.00% |
| 2007 | 70.37% | 28.04% | 1.59% | 0.00% |