Year per Person 1970 0.16923 1971 0.28035 1972 0.40348 1973 0.43719 1974 0.52646 1975 0.54762 1976 0.57956 1977 0.6054 1978 0.57972 1979 0.5854 1980 0.55649 1981 0.55514 1982 0.56403 1983 0.58123 1984 0.56764 1985 0.63243 1986 0.66364 1987 0.69313 1988 0.66569 1989 0.65006 1990 0.7158 1991 0.79481 1992 0.80608 1993 0.94514 1994 1.00625 1995 1.09832 1996 1.3022 1997 1.32436 1998 1.38603 1999 1.51799 2000 1.65455 2001 1.61021 2002 1.57113 2003 1.55491 2004 1.44818 2005 1.31626 2006 1.18358 2007 1.05623 2008 1.00952 2009 0.85636 2010 0.81225 2011 0.63805 2012 0.54462 2013 0.50787 2014 0.50926 2015 0.54475 2016 0.56089