Year	Percent
1950	18.32961
1955	17.0638
1960	18.2556
1965	17.97754
1970	15.68234
1975	13.21003
1980	13.48461
1985	13.66625
1990	13.1044
1995	11.74058
2000	10.22618
2005	8.66425
2010	8.10384
2015	7.45262
2020	6.91503
2025	6.375
2030	5.93202
2035	5.57552
2040	5.29465
2045	5.10057
2050	4.93957
2055	4.80019
2060	4.67254
2065	4.58273
2070	4.52342
2075	4.49565
2080	4.49065
2085	4.48781
2090	4.48522
2095	4.48132
2100	4.48068