Year	Age
1685	17.93
1710	16.95
1735	18.18
1760	18.25
1785	19.03
1800	21.11
1810	20.2
1860	20.79
1879	20.6
1920	21.1
1930	21.8
1940	23.3
1950	23.6
1955	24.7
1960	25
1965	24.8
1970	24.65
1975	24.4
1990	26.7
2005	28.57