Year Percent 1950 15.94272 1955 15.76091 1960 15.82341 1965 16.02181 1970 14.68167 1975 12.70056 1980 12.27009 1985 12.92672 1990 12.961 1995 11.75667 2000 11.71325 2005 9.76078 2010 9.29692 2015 9.72142 2020 9.25948 2025 8.53884 2030 7.97433 2035 7.62148 2040 7.36723 2045 7.08476 2050 6.78596 2055 6.4911 2060 6.21315 2065 5.973 2070 5.77617 2075 5.62681 2080 5.49259 2085 5.35095 2090 5.22515 2095 5.11194 2100 5.0272