Year Percent 1950 16.1721 1955 18.15042 1960 18.21265 1965 18.14435 1970 15.9484 1975 15.07248 1980 14.56065 1985 14.52334 1990 13.66963 1995 12.78002 2000 11.68502 2005 9.87754 2010 8.62161 2015 8.36116 2020 8.1967 2025 7.88339 2030 7.27171 2035 6.57517 2040 6.05131 2045 5.7953 2050 5.73157 2055 5.67698 2060 5.5219 2065 5.2922 2070 5.08195 2075 4.96791 2080 4.95941 2085 4.98995 2090 4.98014 2095 4.90997 2100 4.82171