Year Percent 1950 5.48545 1955 4.77343 1960 4.50809 1965 4.41416 1970 4.364 1975 4.40764 1980 4.65527 1985 5.13299 1990 6.15643 1995 6.91169 2000 7.80156 2005 8.62954 2010 9.34766 2015 10.17916 2020 10.94093 2025 11.81669 2030 12.78197 2035 13.92421 2040 15.18844 2045 16.467 2050 18.33122 2055 21.30542 2060 24.61892 2065 27.04726 2070 29.1572 2075 31.11049 2080 33.04586 2085 34.6832 2090 35.91912 2095 36.80443 2100 37.44461