Year Percent 1950 3.96722 1955 4.37903 1960 5.20286 1965 4.91738 1970 4.86252 1975 4.92306 1980 4.66785 1985 4.50062 1990 4.99447 1995 5.55998 2000 6.52017 2005 7.75815 2010 9.0428 2015 10.79075 2020 12.93259 2025 15.60628 2030 18.54845 2035 20.65355 2040 22.53861 2045 23.9781 2050 25.69862 2055 27.53405 2060 29.25387 2065 30.67809 2070 31.87125 2075 33.26182 2080 34.41517 2085 35.28697 2090 36.03558 2095 36.68151 2100 37.2622