Year	Percent
1950	17.85964
1955	18.20245
1960	18.15509
1965	17.53508
1970	13.64111
1975	11.08999
1980	11.01588
1985	10.00291
1990	9.15183
1995	9.64212
2000	8.12899
2005	7.55674
2010	6.29466
2015	5.31886
2020	5.0267
2025	4.97956
2030	4.97139
2035	4.81183
2040	4.5438
2045	4.29165
2050	4.18009
2055	4.22766
2060	4.32411
2065	4.36341
2070	4.32749
2075	4.26542
2080	4.25248
2085	4.31539
2090	4.41727
2095	4.49558
2100	4.52066