Year	Percent
1950	26.84848
1955	27.01395
1960	27.35878
1965	27.25733
1970	26.91019
1975	27.73586
1980	29.3207
1985	31.40231
1990	32.5158
1995	30.02585
2000	28.93923
2005	26.94221
2010	27.03936
2015	28.35529
2020	29.29834
2025	27.99655
2030	25.934
2035	24.02306
2040	21.47023
2045	20.87648
2050	21.41016
2055	21.07666
2060	20.36072
2065	19.43715
2070	18.74669
2075	18.56923
2080	18.81752
2085	19.08048
2090	19.05806
2095	18.82125
2100	18.58799