Year Percent 1950 9.05458 1955 9.61518 1960 13.06582 1965 14.66073 1970 15.22001 1975 14.21611 1980 13.67279 1985 13.31511 1990 14.14038 1995 15.28462 2000 14.0261 2005 12.65183 2010 10.86713 2015 11.38356 2020 11.91716 2025 11.25894 2030 10.25903 2035 9.37244 2040 8.97511 2045 8.88485 2050 8.69863 2055 8.22836 2060 7.65766 2065 7.20553 2070 6.94749 2075 6.7661 2080 6.54569 2085 6.23813 2090 5.93727 2095 5.69954 2100 5.54623