Year	Percent
1950	8.60057
1955	9.16839
1960	9.98815
1965	11.08567
1970	12.04006
1975	12.91693
1980	11.85105
1985	12.76867
1990	15.73251
1995	17.47168
2000	19.21167
2005	19.63485
2010	21.36911
2015	23.8759
2020	25.80753
2025	26.02327
2030	28.44557
2035	30.64558
2040	32.91202
2045	33.71478
2050	35.4302
2055	35.67955
2060	35.67066
2065	35.58471
2070	35.79944
2075	35.80154
2080	35.85383
2085	35.95447
2090	36.06671
2095	36.24627
2100	36.51188