| Mean | SD | 95 % CI | Mean | SD | 95 % CI | ||
---|---|---|---|---|---|---|---|---|
1920–1929 | 14.00 | 1.82 | 13.76 | 14.23 | 51.78 | 5.19 | 50.92 | 52.75 |
1930–1939 | 13.61 | 1.77 | 13.46 | 13.86 | 51.22 | 5.49 | 50.45 | 52.02 |
1940–1949 | 13.57 | 1.68 | 13.34 | 13.80 | 52.03 | 4.86 | 51.06 | 53.12 |
1950–1959 | 13.31 | 1.34 | 13.14 | 13.49 | 51.25 | 5.21 | 50.65 | 51.93 |
1960–1969 | 12.93 | 1.39 | 12.72 | 13.13 | 49.33 | 3.75 | 48.43 | 50.25 |
1970–1979 | 12.68 | 1.64 | 12.34 | 12.98 | – | – | – | – |
1980–1989 | 12.67 | 1.53 | 12.30 | 13.03 | – | – | – | – |
Together | 13.45 | 1.66 | 13.33 | 13.56 | 51.40 | 5.04 | 51.00 | 51.99 |