Year Percent 1950 6.36937 1955 6.69696 1960 6.87361 1965 6.9717 1970 7.05811 1975 7.11764 1980 7.30923 1985 7.56869 1990 9.12941 1995 9.76186 2000 10.54899 2005 11.79093 2010 13.15495 2015 15.15489 2020 17.41625 2025 19.88951 2030 22.4208 2035 24.56021 2040 26.38457 2045 28.33951 2050 30.5893 2055 32.53159 2060 33.9913 2065 35.07537 2070 36.04943 2075 36.76611 2080 37.35514 2085 37.82159 2090 38.19172 2095 38.50194 2100 38.78415