Year Percent 1950 4.68458 1955 4.34073 1960 4.19767 1965 4.19292 1970 4.21724 1975 4.24286 1980 4.26679 1985 4.2988 1990 4.60093 1995 4.53158 2000 4.16788 2005 3.98407 2010 3.84897 2015 3.81519 2020 3.79486 2025 3.84798 2030 4.05441 2035 4.42846 2040 4.93857 2045 5.5363 2050 6.22928 2055 7.06235 2060 8.02545 2065 9.165 2070 10.42999 2075 11.77756 2080 13.20672 2085 14.69452 2090 16.2261 2095 17.7693 2100 19.28683