Year Percent 1950 11.58734 1955 11.78654 1960 11.64929 1965 11.37729 1970 11.63269 1975 11.74289 1980 11.62789 1985 12.10296 1990 12.5652 1995 12.65525 2000 12.29749 2005 11.98245 2010 12.04559 2015 12.36403 2020 12.51206 2025 12.53061 2030 12.19618 2035 11.85654 2040 11.57941 2045 11.31696 2050 11.02134 2055 10.67014 2060 10.28892 2065 9.91386 2070 9.53057 2075 9.19555 2080 8.88738 2085 8.57064 2090 8.25649 2095 7.95362 2100 7.68391