Year	Percent
1950	17.53974
1955	17.54555
1960	17.59243
1965	17.79882
1970	18.21657
1975	18.64178
1980	18.64897
1985	18.51735
1990	17.85415
1995	16.17757
2000	14.19644
2005	13.78309
2010	13.56003
2015	13.03119
2020	12.37277
2025	11.40358
2030	10.49783
2035	9.81156
2040	9.28291
2045	8.76612
2050	8.21395
2055	7.66463
2060	7.1803
2065	6.7888
2070	6.47471
2075	6.20414
2080	5.96432
2085	5.73826
2090	5.55141
2095	5.39927
2100	5.28066