Year Percent 1950 16.8917 1955 19.04799 1960 17.74508 1965 17.41462 1970 16.13895 1975 12.62395 1980 11.28489 1985 11.1382 1990 11.06158 1995 10.29158 2000 9.60812 2005 9.41475 2010 8.54321 2015 7.99015 2020 7.2257 2025 6.83928 2030 6.61149 2035 6.37619 2040 6.08312 2045 5.77431 2050 5.52606 2055 5.35242 2060 5.2413 2065 5.13959 2070 5.02226 2075 4.88444 2080 4.75301 2085 4.65282 2090 4.58618 2095 4.54139 2100 4.50814