Year Percent 1950 10.88861 1955 17.15114 1960 19.2376 1965 19.4968 1970 18.06701 1975 17.25518 1980 16.65912 1985 17.64511 1990 18.17543 1995 16.32554 2000 14.6339 2005 12.77884 2010 13.4127 2015 13.91687 2020 13.02436 2025 11.77533 2030 10.73356 2035 10.2788 2040 10.15087 2045 9.87512 2050 9.27335 2055 8.57906 2060 8.03965 2065 7.72195 2070 7.48232 2075 7.19149 2080 6.80731 2085 6.43817 2090 6.14502 2095 5.9454 2100 5.78915