Year Percent 1950 5.21572 1955 4.58054 1960 4.32859 1965 4.23797 1970 4.1906 1975 4.21696 1980 4.35642 1985 4.47307 1990 4.83718 1995 4.94639 2000 4.9868 2005 4.87859 2010 4.68214 2015 4.66483 2020 4.71766 2025 4.91511 2030 5.26844 2035 5.81347 2040 6.50937 2045 7.40037 2050 8.29615 2055 9.16308 2060 10.00363 2065 10.936 2070 12.11805 2075 13.49351 2080 14.79878 2085 16.03537 2090 17.25594 2095 18.506 2100 19.80642