Year	Percent
1950	13.20474
1955	14.4313
1960	15.24194
1965	15.07639
1970	15.15067
1975	14.76687
1980	12.66805
1985	12.37706
1990	12.03725
1995	11.15521
2000	10.34969
2005	9.21189
2010	8.5963
2015	7.80998
2020	7.12564
2025	6.59533
2030	6.10695
2035	5.72504
2040	5.41792
2045	5.17573
2050	4.99222
2055	4.83969
2060	4.72139
2065	4.62928
2070	4.56596
2075	4.52597
2080	4.50886
2085	4.49734
2090	4.49794
2095	4.50016
2100	4.50654