Year	% of total population
1960	30.004000000000005
1961	29.623000000000005
1962	29.242999999999995
1963	28.866
1964	28.492000000000004
1965	28.120999999999995
1966	27.753
1967	27.388000000000005
1968	27.025999999999996
1969	26.667
1970	26.397999999999996
1971	26.387
1972	26.376999999999995
1973	26.367000000000004
1974	26.357
1975	26.346999999999994
1976	26.337000000000003
1977	26.326999999999998
1978	26.317999999999998
1979	26.308000000000007
1980	26.262
1981	26.11
1982	25.958
1983	25.805999999999997
1984	25.656000000000006
1985	25.506
1986	25.355999999999995
1987	25.206999999999994
1988	25.058000000000007
1989	24.911
1990	24.700000000000003
1991	24.299000000000007
1992	23.903000000000006
1993	23.512
1994	23.125
1995	22.742999999999995
1996	22.364000000000004
1997	21.992000000000004
1998	21.623000000000005
1999	21.257999999999996
2000	20.942999999999998
2001	20.766000000000005
2002	20.590999999999994
2003	20.417
2004	20.242999999999995
2005	20.072000000000003
2006	19.900999999999996
2007	19.730999999999995
2008	19.561999999999998
2009	19.394000000000005
2010	19.227999999999994
2011	19.055999999999997
2012	18.881
2013	18.700999999999993
2014	18.516999999999996
2015	18.328999999999994
2016	18.138000000000005
2017	17.941999999999993
2018	17.744
2019	17.540999999999997
2020	17.336
2021	17.126999999999995
2022	16.915999999999997
2023	16.701999999999998