Year Percent 1950 8.12071 1955 7.47664 1960 7.03178 1965 6.50184 1970 6.08585 1975 5.94339 1980 5.85652 1985 5.71972 1990 5.96781 1995 5.75083 2000 5.27853 2005 4.83444 2010 4.35584 2015 4.12721 2020 3.73061 2025 3.4777 2030 3.68693 2035 3.82286 2040 4.01622 2045 4.86949 2050 6.76382 2055 9.25428 2060 11.70442 2065 13.46542 2070 14.95051 2075 16.10892 2080 17.17026 2085 18.23454 2090 19.34878 2095 20.54389 2100 21.80395