Year	Percent
1950	19.62012
1955	18.50695
1960	17.84259
1965	19.24278
1970	19.37521
1975	20.33664
1980	21.79844
1985	22.47163
1990	24.98522
1995	26.4283
2000	27.90284
2005	28.90443
2010	26.89939
2015	25.91734
2020	25.34759
2025	25.70846
2030	27.16325
2035	27.96385
2040	27.26944
2045	25.64014
2050	23.68393
2055	22.24964
2060	21.9305
2065	22.36754
2070	22.8729
2075	22.78351
2080	22.33669
2085	21.82057
2090	21.57717
2095	21.7053
2100	21.96447