Year Percent 1950 17.73668 1955 18.51615 1960 16.15908 1965 14.66876 1970 11.87038 1975 9.98895 1980 8.75765 1985 10.22118 1990 8.68397 1995 8.39475 2000 7.68054 2005 6.29705 2010 6.55165 2015 5.39289 2020 5.40033 2025 5.60509 2030 5.81841 2035 5.73509 2040 5.43393 2045 5.14738 2050 5.06027 2055 5.1761 2060 5.3126 2065 5.30738 2070 5.16086 2075 4.98156 2080 4.88484 2085 4.89346 2090 4.95813 2095 4.97968 2100 4.9317