Year Percent 1950 4.51036 1955 4.13638 1960 4.01523 1965 4.05154 1970 4.16002 1975 4.29874 1980 4.43605 1985 4.50142 1990 4.63682 1995 4.60925 2000 4.71098 2005 4.60184 2010 4.43657 2015 4.45102 2020 4.58839 2025 4.832 2030 5.18435 2035 5.66859 2040 6.25548 2045 6.96449 2050 7.6598 2055 8.34216 2060 9.28534 2065 10.44916 2070 11.66045 2075 12.84271 2080 14.05231 2085 15.31711 2090 16.64484 2095 18.02215 2100 19.44069