Year	Percent
1950	28.82722
1955	26.29357
1960	25.96353
1965	23.00893
1970	24.06534
1975	21.85287
1980	27.57594
1985	30.3137
1990	32.80495
1995	31.49984
2000	30.79219
2005	24.99704
2010	22.64972
2015	20.2741
2020	20.26374
2025	21.33973
2030	22.27006
2035	22.80817
2040	22.30211
2045	21.23092
2050	20.11981
2055	20.74307
2060	21.07892
2065	21.35806
2070	21.19474
2075	20.64671
2080	20.02797
2085	19.73287
2090	19.79236
2095	19.89157
2100	19.86381