Year	Percent
1950	15.9949
1955	19.75745
1960	19.51196
1965	19.23917
1970	19.05338
1975	19.55329
1980	19.67467
1985	18.82734
1990	17.23309
1995	15.2376
2000	14.81962
2005	13.78947
2010	12.68136
2015	11.94318
2020	9.81465
2025	9.94418
2030	9.49634
2035	8.93549
2040	8.38528
2045	7.68183
2050	7.0176
2055	6.50677
2060	6.16122
2065	5.90957
2070	5.67883
2075	5.44076
2080	5.21169
2085	5.0222
2090	4.90067
2095	4.83322
2100	4.78564