Year	Percent
1950	17.28926
1955	16.96119
1960	16.90327
1965	16.60588
1970	16.32662
1975	15.71488
1980	14.50051
1985	13.55037
1990	13.39487
1995	14.69682
2000	16.45703
2005	18.2222
2010	20.25104
2015	21.67039
2020	22.9122
2025	24.01181
2030	24.64513
2035	25.28781
2040	26.17055
2045	27.45851
2050	28.22467
2055	28.21794
2060	27.82438
2065	27.10738
2070	26.97548
2075	27.26811
2080	27.43264
2085	27.3129
2090	26.98703
2095	26.6691
2100	26.48029