Year	Percent
1950	17.07756
1955	17.72766
1960	17.98774
1965	17.90727
1970	17.87709
1975	18.23239
1980	18.05262
1985	17.98826
1990	18.05784
1995	18.02323
2000	18.21202
2005	18.28954
2010	17.91434
2015	17.29345
2020	16.52275
2025	15.93202
2030	15.3284
2035	14.64888
2040	13.88527
2045	13.12107
2050	12.38868
2055	11.71967
2060	11.09895
2065	10.50903
2070	9.96286
2075	9.44671
2080	8.9753
2085	8.53599
2090	8.1301
2095	7.77307
2100	7.41362