Year Percent 1950 5.1774 1955 5.22229 1960 5.26202 1965 5.46379 1970 5.67793 1975 5.28965 1980 4.76886 1985 4.56193 1990 4.80822 1995 4.76588 2000 4.58074 2005 4.39457 2010 4.34096 2015 4.64912 2020 5.01134 2025 5.40334 2030 5.85884 2035 6.40845 2040 7.03785 2045 7.6984 2050 8.45986 2055 9.42551 2060 10.60734 2065 11.78988 2070 12.93993 2075 14.0651 2080 15.28666 2085 16.58678 2090 17.91848 2095 19.23852 2100 20.56406