Year Percent 1950 12.48624 1955 14.05374 1960 15.82697 1965 16.51835 1970 16.19483 1975 15.63241 1980 14.5557 1985 12.6259 1990 12.34798 1995 11.65234 2000 13.22678 2005 12.67037 2010 11.22949 2015 9.71477 2020 9.46867 2025 9.17752 2030 8.7164 2035 8.19945 2040 7.71469 2045 7.3118 2050 7.00993 2055 6.74649 2060 6.49496 2065 6.24697 2070 6.04096 2075 5.88166 2080 5.76317 2085 5.66972 2090 5.58273 2095 5.49076 2100 5.4084