Year per Person 1980 6.57631 1981 6.03128 1982 5.7281 1983 9.48777 1984 8.95339 1985 8.51332 1986 8.0058 1987 7.52445 1988 7.17299 1989 6.96743 1990 8.82646 1991 8.67104 1992 7.26428 1993 5.90914 1994 5.90299 1995 5.97389 1996 5.86413 1997 5.61262 1998 7.06292 1999 7.49868 2000 7.21138 2001 7.15996 2002 3.17117 2003 3.09975 2004 2.95781 2005 2.91754 2006 3.06715 2007 3.11236 2008 3.1445 2009 3.96936 2010 4.00385 2011 4.03292 2012 4.05726 2013 4.07809 2014 4.09759 2015 4.1174 2016 4.13791