Year Percent 1950 4.54855 1955 4.22523 1960 4.18861 1965 4.19856 1970 4.16069 1975 4.56039 1980 4.36834 1985 4.18585 1990 4.27524 1995 4.06579 2000 4.05963 2005 3.87457 2010 3.81784 2015 4.0809 2020 4.44958 2025 4.61726 2030 4.64984 2035 4.55995 2040 4.80443 2045 5.28186 2050 5.92914 2055 6.58317 2060 7.05624 2065 7.54207 2070 8.3212 2075 9.28797 2080 10.32493 2085 11.31345 2090 12.21052 2095 13.13068 2100 14.17063