Year Percent 1950 10.68689 1955 8.64017 1960 7.96202 1965 7.45341 1970 7.30566 1975 6.99325 1980 6.57266 1985 6.08606 1990 6.29574 1995 5.95916 2000 5.75374 2005 5.72712 2010 5.67445 2015 5.59846 2020 5.64688 2025 5.83777 2030 6.11857 2035 6.45864 2040 6.86887 2045 7.35159 2050 7.92615 2055 8.6121 2060 9.3836 2065 10.21331 2070 11.12817 2075 12.08936 2080 13.05615 2085 14.04135 2090 15.04681 2095 16.07098 2100 17.12609