Year	Percent
1950	31.45269
1955	29.65065
1960	28.19133
1965	27.05498
1970	28.41418
1975	29.94819
1980	31.92644
1985	33.16746
1990	32.52093
1995	31.79089
2000	29.80693
2005	28.41711
2010	29.10506
2015	28.7495
2020	28.10742
2025	26.70151
2030	25.83991
2035	25.39262
2040	25.70983
2045	25.96149
2050	25.64845
2055	25.11995
2060	24.49448
2065	24.12144
2070	23.97237
2075	23.90316
2080	23.74227
2085	23.42643
2090	23.01619
2095	22.64191
2100	22.35803