Year Percent 1950 8.1305 1955 6.75676 1960 6.58404 1965 8.12249 1970 8.85875 1975 9.98524 1980 9.8183 1985 9.35573 1990 8.5409 1995 9.23435 2000 8.26341 2005 9.07097 2010 8.55022 2015 9.10042 2020 9.29891 2025 9.24507 2030 8.69255 2035 8.15266 2040 7.89003 2045 7.82265 2050 7.76448 2055 7.62884 2060 7.39424 2065 7.12043 2070 6.88048 2075 6.70854 2080 6.57732 2085 6.42859 2090 6.24953 2095 6.05901 2100 5.89248