Year	Percent
1950	15.12506
1955	14.76988
1960	14.29552
1965	13.83059
1970	13.48503
1975	13.33211
1980	13.07788
1985	12.79766
1990	11.74023
1995	14.31528
2000	15.60313
2005	18.2094
2010	21.88295
2015	27.22341
2020	31.37003
2025	31.61547
2030	31.11723
2035	30.2993
2040	29.00706
2045	28.63648
2050	28.24604
2055	27.80089
2060	28.22996
2065	28.46955
2070	28.02598
2075	27.13841
2080	25.95166
2085	25.21561
2090	25.04561
2095	25.17805
2100	25.24721