Year Percent 1950 6.04302 1955 12.73505 1960 13.53362 1965 13.71874 1970 13.09288 1975 9.15181 1980 8.33176 1985 7.77202 1990 6.8775 1995 6.00253 2000 5.71608 2005 4.54299 2010 3.27549 2015 3.40287 2020 3.57653 2025 4.2079 2030 4.36288 2035 4.26685 2040 3.73013 2045 3.43804 2050 3.53511 2055 3.8727 2060 4.22648 2065 4.43134 2070 4.41224 2075 4.27403 2080 4.2211 2085 4.33868 2090 4.54617 2095 4.7021 2100 4.72057