Year	Percent
1950	28.54224
1955	26.19575
1960	26.54476
1965	25.28353
1970	26.69947
1975	28.235
1980	29.03216
1985	28.30243
1990	26.5617
1995	26.73862
2000	28.82408
2005	29.27311
2010	29.18358
2015	26.97675
2020	23.00746
2025	20.97221
2030	20.22465
2035	20.06906
2040	21.19793
2045	21.7539
2050	21.06601
2055	20.36933
2060	20.05201
2065	20.32272
2070	21.0051
2075	21.66042
2080	21.79463
2085	21.42363
2090	20.97086
2095	20.74641
2100	20.79829