Year	Percent
1950	18.31921
1955	18.89705
1960	18.84727
1965	17.33524
1970	16.3578
1975	16.0169
1980	16.9613
1985	18.09167
1990	19.03482
1995	20.92744
2000	22.24133
2005	26.34373
2010	30.20809
2015	32.4271
2020	31.95555
2025	28.82523
2030	26.91251
2035	24.94412
2040	25.2588
2045	25.03339
2050	23.37943
2055	22.85094
2060	22.64987
2065	22.97521
2070	23.3361
2075	22.98584
2080	22.56319
2085	22.26071
2090	22.20783
2095	22.2857
2100	22.31785