Year	Percent
1950	30.06728
1955	29.34132
1960	30.51101
1965	29.05728
1970	28.52976
1975	28.04097
1980	28.13447
1985	30.12095
1990	31.07704
1995	31.79395
2000	30.92772
2005	28.86986
2010	26.0088
2015	23.25406
2020	21.67829
2025	21.25207
2030	21.3895
2035	21.24705
2040	21.00508
2045	20.587
2050	20.16442
2055	20.27354
2060	20.67042
2065	21.10957
2070	21.34372
2075	21.30111
2080	21.09274
2085	20.90201
2090	20.83364
2095	20.85813
2100	20.87627