Year Percent 1950 12.11493 1955 12.03309 1960 13.58209 1965 13.65113 1970 13.65369 1975 13.77491 1980 14.53805 1985 15.0215 1990 15.28802 1995 15.54667 2000 15.86157 2005 16.0285 2010 15.97971 2015 15.67053 2020 15.26476 2025 14.78968 2030 14.25683 2035 13.66786 2040 13.03814 2045 12.41489 2050 11.80198 2055 11.2204 2060 10.67821 2065 10.18571 2070 9.7311 2075 9.30745 2080 8.90117 2085 8.53211 2090 8.18277 2095 7.85306 2100 7.55943