Year Percent 1950 5.16192 1955 4.69537 1960 4.55957 1965 4.45055 1970 4.34355 1975 4.32191 1980 4.0892 1985 4.13457 1990 4.66732 1995 4.85099 2000 4.99051 2005 5.09375 2010 5.41449 2015 6.08033 2020 6.88581 2025 7.84327 2030 9.09173 2035 10.60105 2040 12.51116 2045 14.72773 2050 17.13878 2055 19.78267 2060 22.43944 2065 24.93755 2070 26.98048 2075 28.5298 2080 30.01287 2085 31.3985 2090 32.6184 2095 33.62039 2100 34.4353