Year Percent 1950 8.60095 1955 9.66982 1960 9.49341 1965 8.38279 1970 8.1678 1975 7.74161 1980 7.77978 1985 7.7972 1990 7.02888 1995 6.1804 2000 5.06538 2005 4.54751 2010 4.39441 2015 5.05425 2020 5.23915 2025 5.01045 2030 4.65596 2035 4.35679 2040 4.30968 2045 4.53444 2050 4.81834 2055 4.93325 2060 4.85368 2065 4.71988 2070 4.68262 2075 4.78614 2080 4.94525 2085 5.04022 2090 4.99925 2095 4.8757 2100 4.76837