Year	Percent
1950	16.34574
1955	18.2997
1960	18.1151
1965	18.27341
1970	18.21087
1975	17.91407
1980	18.81573
1985	19.98022
1990	20.10149
1995	19.26746
2000	18.03545
2005	17.23402
2010	17.99169
2015	18.17054
2020	17.59108
2025	16.44957
2030	15.34028
2035	14.71428
2040	14.35061
2045	13.86508
2050	13.15405
2055	12.37241
2060	11.68818
2065	11.17858
2070	10.76597
2075	10.32198
2080	9.82512
2085	9.29833
2090	8.85529
2095	8.46679
2100	8.12787