Year Percent 1950 2.64527 1955 2.93203 1960 3.91802 1965 5.04881 1970 6.65391 1975 8.05348 1980 8.82255 1985 8.71228 1990 10.56011 1995 10.35805 2000 11.49109 2005 12.61409 2010 15.47964 2015 18.37245 2020 21.89538 2025 25.72052 2030 27.9172 2035 29.07858 2040 29.31507 2045 28.67891 2050 27.72175 2055 28.68387 2060 30.01391 2065 31.25127 2070 32.33671 2075 32.54058 2080 32.82108 2085 33.28069 2090 33.94534 2095 34.59502 2100 35.04481