Year Percent 1950 9.2355 1955 10.02808 1960 9.21726 1965 9.17139 1970 9.52829 1975 10.37423 1980 12.93089 1985 11.14899 1990 10.79725 1995 9.32874 2000 9.62053 2005 9.43898 2010 9.31418 2015 8.15478 2020 6.50253 2025 6.79628 2030 6.78407 2035 6.6105 2040 6.39092 2045 6.08735 2050 5.75756 2055 5.55016 2060 5.529 2065 5.55774 2070 5.51456 2075 5.4112 2080 5.29604 2085 5.21543 2090 5.18814 2095 5.19569 2100 5.19762