Year	Percent
1950	31.5114
1955	30.80849
1960	31.92155
1965	29.62871
1970	27.33863
1975	28.78407
1980	30.55907
1985	32.51856
1990	31.74823
1995	30.40052
2000	29.98039
2005	32.45515
2010	35.01019
2015	36.92817
2020	35.57266
2025	31.81355
2030	26.7821
2035	24.54191
2040	24.14363
2045	24.2174
2050	23.36752
2055	21.88132
2060	21.08656
2065	21.09631
2070	21.58645
2075	22.16062
2080	22.36061
2085	22.10444
2090	21.71961
2095	21.56139
2100	21.68879