Year Percent 1950 5.60231 1955 5.15322 1960 4.4979 1965 4.09338 1970 4.34871 1975 4.75265 1980 5.03734 1985 4.99871 1990 5.67465 1995 6.11657 2000 7.15044 2005 8.2822 2010 9.20873 2015 11.15084 2020 13.53551 2025 16.30954 2030 18.43803 2035 20.50428 2040 21.80476 2045 23.66224 2050 25.41887 2055 27.43183 2060 28.81981 2065 29.26896 2070 30.12162 2075 31.06935 2080 31.92716 2085 32.67112 2090 33.27797 2095 33.74315 2100 34.12524