Year Percent 1950 14.25978 1955 13.87918 1960 13.55296 1965 12.29416 1970 12.08642 1975 10.77047 1980 9.87476 1985 9.36826 1990 8.52573 1995 7.72112 2000 7.54666 2005 6.93059 2010 6.28855 2015 5.81087 2020 5.09758 2025 4.83828 2030 4.64516 2035 4.50822 2040 4.33373 2045 4.14049 2050 3.97975 2055 3.88286 2060 3.85887 2065 3.86403 2070 3.86171 2075 3.84409 2080 3.8306 2085 3.83854 2090 3.89069 2095 3.96196 2100 4.02056