Year	Percent
1950	20.3514
1955	18.60016
1960	19.14024
1965	19.52037
1970	19.55251
1975	19.39241
1980	19.60783
1985	19.86748
1990	19.32903
1995	19.49372
2000	20.07562
2005	20.28919
2010	20.25729
2015	20.04222
2020	19.73675
2025	19.39249
2030	18.91409
2035	18.29833
2040	17.5701
2045	16.76736
2050	15.9166
2055	15.05483
2060	14.20119
2065	13.3657
2070	12.54478
2075	11.8137
2080	11.09043
2085	10.44359
2090	9.84721
2095	9.29337
2100	8.7839