Year	Percent
1950	17.58069
1955	18.40217
1960	18.11662
1965	17.96242
1970	16.98383
1975	14.49045
1980	14.04535
1985	13.47126
1990	12.32649
1995	11.27574
2000	9.95246
2005	9.18708
2010	8.26216
2015	7.47164
2020	6.85455
2025	6.29621
2030	5.85809
2035	5.50361
2040	5.22152
2045	5.00364
2050	4.82279
2055	4.68126
2060	4.56993
2065	4.49042
2070	4.43627
2075	4.40602
2080	4.3863
2085	4.38196
2090	4.38286
2095	4.39045
2100	4.39879