Year Percent 1950 5.54495 1955 5.27754 1960 5.23036 1965 5.23333 1970 5.26781 1975 5.2416 1980 5.22376 1985 5.08829 1990 4.93011 1995 4.52903 2000 4.21809 2005 4.19138 2010 4.20552 2015 4.24557 2020 4.3108 2025 4.49203 2030 4.83177 2035 5.38427 2040 6.07826 2045 6.90545 2050 7.7719 2055 8.74438 2060 9.91349 2065 11.2603 2070 12.76201 2075 14.16036 2080 15.49759 2085 16.79436 2090 18.06446 2095 19.29064 2100 20.45982