Year	Percent
1950	4.12507
1955	3.96542
1960	3.86586
1965	3.81233
1970	3.76968
1975	3.7982
1980	3.89421
1985	4.09394
1990	4.6285
1995	5.08762
2000	5.44945
2005	5.70009
2010	6.20952
2015	6.85052
2020	8.02375
2025	9.28809
2030	11.26314
2035	13.34138
2040	16.2135
2045	19.89184
2050	23.65111
2055	26.80099
2060	29.21187
2065	31.00021
2070	32.59828
2075	33.81748
2080	34.95732
2085	35.8434
2090	36.43894
2095	36.80072
2100	37.04496