Year Percent 1950 4.9053 1955 4.8104 1960 4.8073 1965 4.70876 1970 4.65174 1975 4.60142 1980 4.55927 1985 4.61576 1990 4.78874 1995 4.751 2000 4.68961 2005 4.60065 2010 4.54185 2015 4.47505 2020 4.51597 2025 4.62235 2030 4.79066 2035 5.10684 2040 5.54126 2045 6.00537 2050 6.43078 2055 6.86206 2060 7.42988 2065 8.20972 2070 9.15336 2075 10.22144 2080 11.29904 2085 12.41849 2090 13.59339 2095 14.82669 2100 16.10124