Year Percent 1950 5.37491 1955 4.54596 1960 4.2779 1965 4.24963 1970 4.25346 1975 4.62603 1980 4.61741 1985 4.61169 1990 5.0321 1995 5.41554 2000 6.01792 2005 6.57235 2010 6.85482 2015 7.05648 2020 7.92504 2025 9.68648 2030 11.89395 2035 14.11915 2040 16.92782 2045 20.04878 2050 23.13841 2055 26.02793 2060 28.83528 2065 31.46769 2070 33.59161 2075 35.37836 2080 36.93067 2085 38.19868 2090 39.16825 2095 39.84457 2100 40.29046