Year	% of total population
1960	21.555999999999997
1961	21.626000000000005
1962	21.763000000000005
1963	21.900999999999996
1964	22.040000000000006
1965	22.179000000000002
1966	22.317999999999998
1967	22.459000000000003
1968	22.599999999999994
1969	22.741
1970	22.882999999999996
1971	22.97
1972	22.805000000000007
1973	22.641999999999996
1974	22.479
1975	22.316999999999993
1976	22.156000000000006
1977	21.995000000000005
1978	21.836
1979	21.677000000000007
1980	21.519000000000005
1981	21.412000000000006
1982	21.461
1983	21.510999999999996
1984	21.560000000000002
1985	21.61
1986	21.659999999999997
1987	21.709999999999994
1988	21.760000000000005
1989	21.810000000000002
1990	21.86
1991	21.888000000000005
1992	21.828000000000003
1993	21.768
1994	21.706999999999994
1995	21.647000000000006
1996	21.587000000000003
1997	21.528000000000006
1998	21.468000000000004
1999	21.409000000000006
2000	21.349000000000004
2001	21.248999999999995
2002	20.953000000000003
2003	20.661
2004	20.370999999999995
2005	20.084999999999994
2006	19.801000000000002
2007	19.521
2008	19.242999999999995
2009	18.968999999999994
2010	18.697999999999993
2011	18.430000000000007
2012	18.162999999999997
2013	17.897999999999996
2014	17.635000000000005
2015	17.373999999999995
2016	17.114000000000004
2017	16.857
2018	16.602000000000004
2019	16.348
2020	16.096999999999994
2021	15.847999999999999
2022	15.602000000000004
2023	15.358000000000004