Year Percent 1950 14.2328 1955 15.04039 1960 15.51061 1965 15.5636 1970 15.18231 1975 14.52809 1980 13.80365 1985 13.1569 1990 12.56814 1995 12.20573 2000 12.02733 2005 11.97337 2010 12.11843 2015 12.34713 2020 12.81973 2025 13.42166 2030 13.9786 2035 14.6164 2040 15.32587 2045 16.21842 2050 17.37755 2055 18.52202 2060 19.55634 2065 20.44522 2070 21.18808 2075 21.89631 2080 22.56022 2085 23.12885 2090 23.56858 2095 23.90344 2100 24.15362