Year	Percent
1950	13.36977
1955	13.00988
1960	14.83708
1965	14.77078
1970	14.60456
1975	14.53659
1980	14.1034
1985	13.37044
1990	12.80892
1995	12.43592
2000	11.80709
2005	11.17482
2010	10.30966
2015	9.92742
2020	9.47512
2025	8.92623
2030	8.38604
2035	7.88315
2040	7.43895
2045	7.04262
2050	6.68133
2055	6.35347
2060	6.05649
2065	5.80084
2070	5.58428
2075	5.40218
2080	5.25464
2085	5.12856
2090	5.02142
2095	4.93069
2100	4.85881