Year Percent 1950 8.92728 1955 10.69182 1960 9.38497 1965 9.11583 1970 9.16052 1975 8.56156 1980 7.22774 1985 5.91898 1990 5.74787 1995 5.9748 2000 6.05472 2005 5.83687 2010 5.8168 2015 5.34302 2020 5.04586 2025 5.07921 2030 5.13032 2035 5.10334 2040 5.02168 2045 4.90831 2050 4.822 2055 4.82966 2060 4.90755 2065 4.95343 2070 4.93501 2075 4.86503 2080 4.79608 2085 4.76782 2090 4.77919 2095 4.79024 2100 4.77595