Year Percent 1950 4.42188 1955 4.16281 1960 4.24048 1965 4.65693 1970 5.16708 1975 5.57623 1980 5.86635 1985 5.91219 1990 6.2196 1995 5.83773 2000 5.35122 2005 5.01831 2010 4.63721 2015 4.47695 2020 4.31406 2025 4.25347 2030 4.39374 2035 4.72683 2040 5.14242 2045 5.56598 2050 5.96822 2055 6.47882 2060 7.16028 2065 8.14046 2070 9.41281 2075 10.75442 2080 12.11898 2085 13.57012 2090 15.11694 2095 16.72383 2100 18.33639