Year Percent 1950 10.43477 1955 12.68504 1960 12.97049 1965 12.13158 1970 12.14574 1975 10.60367 1980 9.70967 1985 8.60302 1990 8.17527 1995 7.64703 2000 6.82318 2005 6.21381 2010 4.77131 2015 4.88289 2020 4.63303 2025 4.65704 2030 4.76183 2035 4.68004 2040 4.42653 2045 4.23321 2050 4.21059 2055 4.31368 2060 4.44982 2065 4.51285 2070 4.46782 2075 4.39835 2080 4.39675 2085 4.48081 2090 4.59475 2095 4.66126 2100 4.64933