Year Percent 1950 4.09559 1955 4.31116 1960 4.4194 1965 4.59053 1970 4.71614 1975 4.8003 1980 4.76469 1985 4.6034 1990 4.41753 1995 3.91669 2000 3.49803 2005 3.25954 2010 3.12312 2015 3.08134 2020 3.2037 2025 3.44951 2030 3.80624 2035 4.21647 2040 4.75307 2045 5.35623 2050 5.95199 2055 6.59205 2060 7.32855 2065 8.19965 2070 9.23279 2075 10.30739 2080 11.38836 2085 12.48662 2090 13.63007 2095 14.82408 2100 16.05371