Percentage of homes reported as smoke- free by parental smoking habits
| Parental smoking habits | |||
| No parent smokes | One or both parents smoke | All children | |
| 1998 | 95.5 (93.9–96.7) | 15.7 (12.9–18.9) | 64.1 (61.5–66.7) |
| 1271 | 824 | 2095 | |
| 2001 | 96.5 (94.9–97.6) | 19.7 (16.3–23.6) | 68.6 (65.8–71.2) |
| 1144 | 654 | 1798 | |
| 2002 | 95.5 (93.1–97.0) | 22.6 (18.0–28.8) | 68.0 (64.5–71.3) |
| 662 | 402 | 1064 | |
| 2003 | 95.1 (92.7–96.7) | 23.2 (18.7–28.4) | 68.1 (64.5–71.5) |
| 1028 | 615 | 1643 | |
| 2005 | 97.3 (95.0–98.5) | 31.2 (23.7–39.9) | 73.7 (68.9–77.9) |
| 459 | 247 | 706 | |
| 2006 | 97.6 (95.8–98.6) | 35.5 (29.7–41.7) | 76.6 (73.2–79.6) |
| 951 | 460 | 1411 | |
| 2007 January–June | 98.3 (94.1–99.5) | 30.5 (19.7–43.9) | 78.1 (71.8–83.3) |
| 243 | 98 | 341 | |
| 2007 July+ | 97.9 (93.7–99.3) | 40.0 (28.6–52.6) | 77.2 (70.5–82.8) |
| 235 | 118 | 354 | |
| 2008 | 96.4 (95.1–97.4) | 48.1 (43.0–53.1) | 80.4 (78.2–82.4) |
| 972 | 445 | 1417 | |