Number of confirmed non-smoking children aged 4–15 each year, and parental smoking habits
| Total number of confirmed non-smoking children aged 4–15 | Parental smoking habits | ||
| No parental smoking | One or both parents smoke | ||
| 1998 | 2095 | 60.7 (58.0–63.3) | 39.3 (36.7–42.0) |
| 2001 | 1799 | 63.6 (60.8–66.3) | 36.4 (33.7–39.2) |
| 2002 | 1064 | 62.2 (58.7–65.6) | 37.8 (34.4–41.3) |
| 2003 | 1643 | 62.5 (58.8–66.0) | 37.5 (34.0–41.2) |
| 2005 | 706 | 64.3 (59.2–69.1) | 35.7 (30.9–40.8) |
| 2006 | 1411 | 66.2 (62.6–69.5) | 33.8 (30.5–37.4) |
| 2007 January–June | 339 | 69.8 (63.4–75.6) | 29.9 (24.2–36.3) |
| 2007 July–December | 353 | 64.7 (57.3–71.4) | 35.2 (28.5–42.6) |
| 2008 | 1415 | 66.9 (64.3–69.4) | 33.1 (30.6–35.7) |