Year	Percent
1950	4.59191
1955	4.44152
1960	4.39954
1965	4.40993
1970	4.66117
1975	5.09256
1980	6.1519
1985	6.83384
1990	8.28658
1995	9.06794
2000	10.00897
2005	10.88678
2010	13.42125
2015	16.93667
2020	20.03492
2025	23.46412
2030	25.78547
2035	27.43767
2040	29.9299
2045	31.30494
2050	32.72179
2055	35.13169
2060	36.88726
2065	38.68798
2070	39.49239
2075	39.42958
2080	39.1975
2085	39.05904
2090	39.05278
2095	39.04809
2100	38.97664