Year Percent 1950 28.42609 1955 28.76627 1960 28.8312 1965 28.75603 1970 28.46478 1975 27.65767 1980 27.4145 1985 26.5013 1990 26.27337 1995 26.90372 2000 27.76851 2005 28.38002 2010 28.48996 2015 28.14766 2020 27.9412 2025 28.2762 2030 29.06739 2035 30.08197 2040 30.83444 2045 31.22358 2050 31.41556 2055 31.47598 2060 31.55011 2065 31.57385 2070 31.47496 2075 31.2647 2080 30.96065 2085 30.62242 2090 30.28363 2095 29.92298 2100 29.54877