Year per Person 1980 9.06976 1981 8.75406 1982 9.66609 1983 9.41759 1984 9.09352 1985 10.48022 1986 11.61367 1987 9.90243 1988 8.67816 1989 11.69659 1990 13.16067 1991 14.0458 1992 13.64972 1993 15.06174 1994 15.16162 1995 14.74331 1996 14.33385 1997 14.11304 1998 13.72882 1999 13.54263 2000 13.21687 2001 12.9362 2002 13.16721 2003 14.98685 2004 14.65746 2005 14.2665 2006 13.79859 2007 13.01903 2008 11.95546 2009 12.31699 2010 12.20334 2011 12.29391 2012 12.56078 2013 12.94857 2014 13.35723 2015 13.69096 2016 13.91718