Year	Percent
1950	18.27629
1955	19.0348
1960	18.39774
1965	17.92254
1970	17.24146
1975	15.76073
1980	15.96857
1985	16.19137
1990	15.50892
1995	14.36918
2000	13.28659
2005	11.54409
2010	10.87249
2015	10.14876
2020	9.72356
2025	9.14476
2030	8.49066
2035	7.8805
2040	7.39683
2045	7.00106
2050	6.67288
2055	6.36668
2060	6.07308
2065	5.81283
2070	5.60546
2075	5.43415
2080	5.28037
2085	5.15498
2090	5.05731
2095	4.97809
2100	4.90558