Year	Percent
1950	29.71908
1955	29.43364
1960	29.33692
1965	27.83069
1970	26.22607
1975	26.20217
1980	26.23661
1985	27.63611
1990	27.99578
1995	29.03212
2000	29.32576
2005	28.60145
2010	26.47703
2015	23.82605
2020	21.77454
2025	20.81997
2030	20.5457
2035	20.05665
2040	19.01727
2045	17.92457
2050	17.14983
2055	16.9907
2060	17.4102
2065	18.00172
2070	18.35527
2075	18.3912
2080	18.27077
2085	18.22927
2090	18.40629
2095	18.73974
2100	19.0259