Year Percent 1950 11.65128 1955 11.45166 1960 11.45835 1965 13.48216 1970 13.24111 1975 12.97978 1980 12.57023 1985 12.16019 1990 11.99136 1995 11.81521 2000 11.73826 2005 11.28673 2010 10.77952 2015 10.00085 2020 9.71635 2025 9.41063 2030 9.09064 2035 8.72951 2040 8.37151 2045 8.03421 2050 7.70345 2055 7.40026 2060 7.12511 2065 6.85763 2070 6.58881 2075 6.35157 2080 6.14094 2085 5.95879 2090 5.79455 2095 5.64588 2100 5.51511