Year	Percent
1950	29.40374
1955	27.94949
1960	27.23966
1965	26.38735
1970	28.58295
1975	32.25259
1980	37.06395
1985	40.44562
1990	42.43704
1995	38.58477
2000	33.86388
2005	32.02852
2010	30.54546
2015	28.18074
2020	26.05827
2025	24.16298
2030	22.84051
2035	21.14293
2040	19.81244
2045	18.96771
2050	18.53772
2055	18.30496
2060	18.11453
2065	17.92902
2070	17.69979
2075	17.52277
2080	17.43304
2085	17.39457
2090	17.34843
2095	17.26808
2100	17.14174