Year	Percent
1950	27.78535
1955	27.38785
1960	26.88411
1965	26.50072
1970	27.37094
1975	28.55788
1980	30.58448
1985	32.41595
1990	32.56123
1995	32.16841
2000	31.87765
2005	31.73897
2010	31.99497
2015	32.51774
2020	32.03614
2025	30.29712
2030	28.40076
2035	26.59441
2040	25.11518
2045	24.17505
2050	23.18704
2055	22.31983
2060	21.55961
2065	21.00383
2070	20.61855
2075	20.36875
2080	20.20838
2085	20.08813
2090	19.98963
2095	19.91287
2100	19.87104