Year Percent 1950 8.75106 1955 8.03001 1960 11.1235 1965 12.20899 1970 11.10886 1975 8.8398 1980 8.98625 1985 8.92865 1990 9.51386 1995 9.63796 2000 7.7483 2005 5.78152 2010 5.13585 2015 5.31343 2020 5.50389 2025 4.99122 2030 4.51102 2035 4.20407 2040 4.03265 2045 4.08565 2050 4.2319 2055 4.28919 2060 4.22395 2065 4.14752 2070 4.16204 2075 4.29267 2080 4.4765 2085 4.61387 2090 4.6408 2095 4.59595 2100 4.56673