Year	Percent
1950	29.89737
1955	28.39748
1960	28.78398
1965	26.9982
1970	26.97874
1975	28.88754
1980	30.61121
1985	31.29381
1990	30.57493
1995	29.88801
2000	30.61679
2005	31.63837
2010	32.08056
2015	30.79961
2020	27.56369
2025	24.40295
2030	22.27887
2035	21.1853
2040	21.45199
2045	22.01586
2050	21.80177
2055	21.18064
2060	20.58225
2065	20.37065
2070	20.66057
2075	21.22487
2080	21.60847
2085	21.55675
2090	21.2207
2095	20.90468
2100	20.80117