Year	Percent
1950	20.26778
1955	20.52691
1960	20.24886
1965	19.45284
1970	17.96255
1975	17.32844
1980	17.73105
1985	18.81576
1990	19.54582
1995	19.97474
2000	20.84821
2005	22.12868
2010	24.83057
2015	26.58666
2020	26.36024
2025	24.98098
2030	24.57956
2035	24.82953
2040	25.67693
2045	26.56868
2050	26.49526
2055	25.9127
2060	25.59649
2065	25.44824
2070	25.39541
2075	25.1115
2080	24.75651
2085	24.4085
2090	24.10618
2095	23.8763
2100	23.71353