Year Percent 1950 4.19535 1955 4.66188 1960 5.41595 1965 6.08258 1970 6.28728 1975 6.10105 1980 5.75274 1985 5.34152 1990 5.54897 1995 5.32756 2000 5.18211 2005 5.06573 2010 4.75185 2015 5.01735 2020 4.98236 2025 5.20329 2030 5.95202 2035 6.80074 2040 7.64656 2045 8.40281 2050 9.14716 2055 9.88213 2060 10.67459 2065 11.42812 2070 12.33742 2075 13.42386 2080 14.52563 2085 15.62492 2090 16.75227 2095 17.92974 2100 19.15437