Year	Percent
1950	17.88922
1955	18.21558
1960	18.84542
1965	19.39692
1970	19.31802
1975	19.50846
1980	19.26455
1985	18.582
1990	18.16821
1995	17.98407
2000	18.15287
2005	18.27507
2010	17.55937
2015	16.79747
2020	16.30337
2025	15.80718
2030	15.21364
2035	14.54867
2040	13.8952
2045	13.31905
2050	12.79513
2055	12.29334
2060	11.76062
2065	11.26038
2070	10.78908
2075	10.35478
2080	9.94698
2085	9.54589
2090	9.15778
2095	8.78645
2100	8.43119