Year Percent 1950 8.69203 1955 8.98185 1960 8.78922 1965 9.45232 1970 9.56585 1975 9.06963 1980 8.79552 1985 8.22141 1990 6.48088 1995 5.31772 2000 4.81205 2005 4.52312 2010 4.9035 2015 5.29652 2020 4.68706 2025 4.30445 2030 3.99251 2035 3.88348 2040 3.97532 2045 4.16025 2050 4.28979 2055 4.2711 2060 4.19175 2065 4.16862 2070 4.23535 2075 4.36286 2080 4.48025 2085 4.51868 2090 4.47826 2095 4.40488 2100 4.36359