Year	Percent
1950	18.32212
1955	19.1441
1960	19.0576
1965	19.14516
1970	19.36905
1975	19.32967
1980	19.42993
1985	19.56574
1990	19.75267
1995	20.15566
2000	20.14303
2005	20.09222
2010	19.55006
2015	18.71258
2020	17.87122
2025	17.05467
2030	16.22334
2035	15.34248
2040	14.44287
2045	13.58939
2050	12.78818
2055	12.04691
2060	11.34848
2065	10.68534
2070	10.07083
2075	9.50304
2080	8.97649
2085	8.49449
2090	8.04905
2095	7.64072
2100	7.26211