Year Percent 1950 10.89565 1955 11.48522 1960 11.33682 1965 11.06966 1970 11.46281 1975 12.08558 1980 12.44238 1985 12.75753 1990 12.45625 1995 13.23072 2000 14.09369 2005 15.87904 2010 17.26162 2015 18.00381 2020 17.92651 2025 17.18345 2030 15.9141 2035 15.79978 2040 16.55185 2045 17.99941 2050 20.70707 2055 22.05983 2060 22.33822 2065 22.19566 2070 21.36133 2075 21.42804 2080 22.27137 2085 23.07191 2090 23.33369 2095 22.95959 2100 22.42763