Year Percent 1950 9.17083 1955 9.86578 1960 7.49929 1965 6.95259 1970 9.50961 1975 9.72949 1980 9.00755 1985 7.65318 1990 7.4309 1995 7.96796 2000 9.03125 2005 9.46339 2010 7.70649 2015 5.63721 2020 4.58637 2025 5.00908 2030 5.21345 2035 4.7973 2040 4.36962 2045 4.09575 2050 3.94679 2055 4.02383 2060 4.20166 2065 4.29983 2070 4.27881 2075 4.24134 2080 4.28042 2085 4.41558 2090 4.58633 2095 4.70319 2100 4.71798