Year Percent 1950 5.28632 1955 5.21511 1960 5.18059 1965 5.19232 1970 5.22093 1975 5.31059 1980 5.47785 1985 5.66681 1990 6.67943 1995 7.11476 2000 7.68075 2005 8.38889 2010 9.2078 2015 10.22525 2020 11.57671 2025 13.19229 2030 14.97314 2035 16.85803 2040 18.62273 2045 20.23651 2050 21.73693 2055 23.10365 2060 24.4909 2065 25.78531 2070 27.1088 2075 28.5115 2080 29.80634 2085 31.01978 2090 32.15972 2095 33.21146 2100 34.15252