Year	Percent
1950	30.25365
1955	31.14892
1960	32.31728
1965	33.23887
1970	34.25218
1975	32.98103
1980	30.89688
1985	28.86385
1990	26.54747
1995	26.70856
2000	26.72667
2005	26.0727
2010	24.44437
2015	21.64286
2020	20.02337
2025	18.95258
2030	18.50106
2035	18.4289
2040	18.29316
2045	18.21654
2050	18.0742
2055	17.94669
2060	17.98332
2065	18.19874
2070	18.49093
2075	18.73059
2080	18.82146
2085	18.81694
2090	18.78213
2095	18.76636
2100	18.77825