Year Percent 1950 8.12719 1955 7.03936 1960 7.9204 1965 8.23494 1970 8.83941 1975 8.4357 1980 6.03829 1985 5.40274 1990 5.72351 1995 6.02574 2000 5.38865 2005 5.10305 2010 4.67979 2015 4.47848 2020 4.53417 2025 4.70264 2030 4.78112 2035 4.67122 2040 4.49435 2045 4.38995 2050 4.41159 2055 4.5458 2060 4.68673 2065 4.74346 2070 4.70657 2075 4.63999 2080 4.60514 2085 4.63461 2090 4.68221 2095 4.71279 2100 4.69436