Year	Percent
1950	30.37116
1955	30.38655
1960	30.48368
1965	29.39607
1970	28.18311
1975	26.30405
1980	26.64501
1985	27.22346
1990	27.26383
1995	27.70536
2000	27.98604
2005	27.1226
2010	27.05708
2015	27.05217
2020	26.73196
2025	26.68668
2030	26.17101
2035	25.25685
2040	24.4827
2045	23.94374
2050	23.48732
2055	23.01761
2060	22.52184
2065	22.02728
2070	21.59256
2075	21.25827
2080	21.00756
2085	20.79258
2090	20.59681
2095	20.41278
2100	20.24961