| Birth cohort | Men | Women | ||||||||||||
| 15–19 | 20–24 | 25–29 | 30–34 | 35–39 | 40–44 | 45–49 | 15–19 | 20–24 | 25–29 | 30–34 | 35–39 | 40–44 | 45–49 | |
| Before 1955 | 20.0 | 20.0 | 19.3 | 19.0 | ||||||||||
| (22) | (224) | (42) | (436) | |||||||||||
| 1955–9 | 19.5 | 20.0 | 20.0 | 19.0 | 19.0 | 18.7 | ||||||||
| (23) | (257) | (172) | (50) | (667) | (544) | |||||||||
| 1960–4 | 19.0 | 19.0 | 19.0 | 18.3 | 18.0 | 18.0 | ||||||||
| (48) | (379) | (239) | (65) | (816) | (671) | |||||||||
| 1965–9 | 19.3 | 19.0 | 19.3 | 18.0 | 18.3 | 18.0 | ||||||||
| (45) | (352) | (231) | (69) | (656) | (496) | |||||||||
| 1970–4 | 18.8 | 19.0 | 19.0 | 18.0 | 18.3 | 18.3 | ||||||||
| (68) | (609) | (388) | (62) | (750) | (599) | |||||||||
| After 1975 | 17.0 | 18.0 | 18.3 | 17.0 | 18.0 | 18.6 | ||||||||
| (415) | (1047) | (458) | (448) | (1103) | (586) | |||||||||
Data include all reports after corrections and estimations for inconsistent reports have been made. Small sample sizes are indicated in italic, along the leftmost diagonal for men and for women. These are low due to the timing of the surveys in relation to birth cohorts (eg, the majority of individuals in the 1970–4 birth cohort had aged past the 20–24 age group when they were surveyed).