Year Percent 1950 3.01768 1955 3.31406 1960 3.57191 1965 3.79843 1970 3.96934 1975 4.09304 1980 4.16629 1985 4.23136 1990 4.48391 1995 4.45688 2000 4.31776 2005 4.19563 2010 4.15357 2015 4.35663 2020 4.75283 2025 5.2275 2030 5.76888 2035 6.38335 2040 7.03332 2045 7.69082 2050 8.34123 2055 8.95634 2060 9.55028 2065 10.16394 2070 10.86279 2075 11.67375 2080 12.4642 2085 13.21202 2090 13.92159 2095 14.61446 2100 15.31634