Year Percent 1950 3.98757 1955 4.25901 1960 4.45747 1965 4.58472 1970 4.6441 1975 4.69547 1980 4.66989 1985 4.42338 1990 4.3934 1995 4.08973 2000 4.03461 2005 4.07681 2010 4.18298 2015 4.27208 2020 4.32786 2025 4.2909 2030 4.27112 2035 4.2931 2040 4.34104 2045 4.48444 2050 4.79566 2055 5.25601 2060 5.90134 2065 6.54482 2070 7.25656 2075 8.00053 2080 8.83653 2085 9.71757 2090 10.62899 2095 11.56028 2100 12.50773