Year Percent 1950 5.74275 1955 5.24501 1960 5.11086 1965 5.27218 1970 6.37084 1975 7.15826 1980 7.58615 1985 7.70694 1990 9.15397 1995 9.69047 2000 10.67167 2005 12.02351 2010 13.58616 2015 15.43646 2020 17.83411 2025 20.70346 2030 22.33828 2035 23.99058 2040 25.93939 2045 29.22867 2050 31.55987 2055 32.36185 2060 32.31322 2065 32.57502 2070 33.33692 2075 34.18298 2080 34.6061 2085 34.68552 2090 34.65685 2095 34.72775 2100 34.96537