Year Percent 1950 5.08761 1955 4.66537 1960 4.16448 1965 4.27089 1970 4.49299 1975 4.55341 1980 4.59872 1985 4.11256 1990 3.94103 1995 3.96217 2000 3.81926 2005 3.77893 2010 3.49367 2015 3.60616 2020 3.88757 2025 4.30305 2030 4.81356 2035 5.18269 2040 5.80532 2045 6.42453 2050 7.01008 2055 7.69613 2060 8.59023 2065 9.6958 2070 10.97047 2075 12.39913 2080 13.87484 2085 15.36585 2090 16.85304 2095 18.32898 2100 19.75721