Year	Percent
1950	29.17915
1955	30.51202
1960	32.29354
1965	33.83038
1970	35.03763
1975	33.8458
1980	31.77991
1985	29.80703
1990	27.45978
1995	27.68263
2000	27.75086
2005	27.14393
2010	25.53732
2015	22.64946
2020	21.00897
2025	19.91506
2030	19.46631
2035	19.41078
2040	19.27485
2045	19.18482
2050	19.02461
2055	18.89818
2060	18.95558
2065	19.19039
2070	19.47882
2075	19.68474
2080	19.73539
2085	19.69636
2090	19.63856
2095	19.60916
2100	19.61103