Year Percent 1950 8.55773 1955 9.13866 1960 8.24014 1965 8.67209 1970 8.14342 1975 8.02813 1980 7.34499 1985 7.29164 1990 6.49958 1995 5.19348 2000 4.85834 2005 4.84357 2010 4.65959 2015 4.92897 2020 4.33711 2025 3.86014 2030 3.60115 2035 3.61758 2040 3.74477 2045 3.8934 2050 3.94117 2055 3.86218 2060 3.77307 2065 3.78935 2070 3.92409 2075 4.10105 2080 4.22955 2085 4.26221 2090 4.22262 2095 4.1876 2100 4.20619