Year Percent 1950 12.26008 1955 12.09599 1960 15.074 1965 15.68475 1970 15.96984 1975 15.15468 1980 14.04823 1985 13.69498 1990 13.71456 1995 12.33653 2000 11.39204 2005 9.93793 2010 9.39169 2015 9.04016 2020 9.25089 2025 8.51276 2030 7.7818 2035 7.15587 2040 6.71041 2045 6.43191 2050 6.22531 2055 5.99421 2060 5.72021 2065 5.45227 2070 5.24405 2075 5.11238 2080 5.03181 2085 4.96076 2090 4.86913 2095 4.77017 2100 4.684