Year	Percent
1950	29.41214
1955	27.23784
1960	27.73287
1965	27.14171
1970	28.89499
1975	30.71701
1980	31.66936
1985	30.86517
1990	29.03462
1995	29.28921
2000	31.61154
2005	32.04903
2010	32.17937
2015	29.53655
2020	25.03959
2025	22.6414
2030	21.73427
2035	21.54826
2040	22.68454
2045	23.18249
2050	22.36531
2055	21.56898
2060	21.20468
2065	21.46958
2070	22.15095
2075	22.77922
2080	22.85081
2085	22.40482
2090	21.88886
2095	21.64372
2100	21.71212