Year Percent 1950 16.25396 1955 20.00545 1960 19.40919 1965 19.2884 1970 19.16437 1975 19.72087 1980 20.27206 1985 20.00742 1990 20.03428 1995 19.61997 2000 19.20812 2005 19.33244 2010 19.30792 2015 18.5158 2020 17.65118 2025 16.96464 2030 16.35031 2035 15.70114 2040 15.01178 2045 14.29193 2050 13.58048 2055 12.91527 2060 12.30079 2065 11.73361 2070 11.19596 2075 10.67399 2080 10.18396 2085 9.73389 2090 9.30794 2095 8.91143 2100 8.53262