Age-specific percentiles of time since quitting smoking in the Health Survey for England 2008
| Age group | Median time since quitting (years) | Extrapolated number of years since quitting | Extrapolated age when they quit |
|---|---|---|---|
| <20 | 2 | * | * |
| 20–29 | 3 | * | * |
| 30–39 | 5 | 14 | 16—25 |
| 40–49 | 10 | 22 | 18—27 |
| 50–59 | 20 | 30 | 20—29 |
| 60–69 | 24 | 35 | 25—34 |
| 70–79 | 30 | 42 | 28—37 |
| 80–89 | 32 | 40 | 40—49 |
| 90+ | 40 | 46 | 44+ |
*Not possible to assign an optimal value for reclassification to these age groups.