Year Percent 1950 13.02507 1955 12.29937 1960 15.07436 1965 14.55554 1970 13.53095 1975 13.51366 1980 12.31176 1985 9.62569 1990 11.49244 1995 10.52038 2000 9.61428 2005 9.69043 2010 8.89173 2015 8.10124 2020 7.6263 2025 7.34554 2030 7.07455 2035 6.72931 2040 6.3554 2045 6.05274 2050 5.85196 2055 5.73458 2060 5.63519 2065 5.51073 2070 5.36329 2075 5.23077 2080 5.13091 2085 5.08132 2090 5.04306 2095 4.99589 2100 4.93164