Year Percent 1950 14.88432 1955 15.33365 1960 15.10134 1965 14.70919 1970 14.57473 1975 14.69917 1980 15.09432 1985 15.21058 1990 15.056 1995 15.56484 2000 17.00707 2005 18.83129 2010 20.98877 2015 22.87918 2020 24.08756 2025 25.05227 2030 25.38525 2035 25.44906 2040 25.47872 2045 25.6199 2050 25.89027 2055 26.42868 2060 26.72412 2065 26.6226 2070 26.46195 2075 26.04718 2080 25.80537 2085 25.65573 2090 25.50597 2095 25.28324 2100 25.0014