Year	Percent
1950	28.09426
1955	28.24407
1960	28.37737
1965	27.31997
1970	27.53365
1975	27.88509
1980	30.75633
1985	33.72114
1990	36.34582
1995	37.35433
2000	35.43641
2005	33.45814
2010	29.48738
2015	27.30897
2020	25.65148
2025	23.05685
2030	21.36544
2035	19.15481
2040	17.7387
2045	17.64572
2050	18.07102
2055	18.49076
2060	18.50158
2065	18.23578
2070	17.88394
2075	17.80661
2080	18.21379
2085	18.82424
2090	19.21923
2095	19.23246
2100	18.93046