Year Percent 1950 12.10046 1955 11.95854 1960 11.90383 1965 11.89493 1970 11.72153 1975 11.46641 1980 11.38204 1985 11.79584 1990 12.14057 1995 12.78759 2000 13.44312 2005 14.81146 2010 16.05553 2015 16.79531 2020 17.66235 2025 18.40695 2030 19.95233 2035 20.74943 2040 21.53391 2045 21.70445 2050 21.99936 2055 22.49668 2060 22.90484 2065 23.39055 2070 23.40535 2075 23.58679 2080 23.73922 2085 23.8913 2090 24.00483 2095 24.03353 2100 24.00261