Year Percent 1950 3.66041 1955 3.99548 1960 4.23472 1965 4.54715 1970 4.81716 1975 5.04523 1980 5.14322 1985 5.11338 1990 5.09129 1995 4.6855 2000 4.32078 2005 4.07929 2010 3.90132 2015 3.83761 2020 3.92672 2025 4.13186 2030 4.441 2035 4.80647 2040 5.30818 2045 5.889 2050 6.48501 2055 7.14458 2060 7.9184 2065 8.8432 2070 9.94396 2075 11.10298 2080 12.28305 2085 13.48807 2090 14.7411 2095 16.0369 2100 17.35746