Year per Person 1980 22.07509 1981 22.166 1982 21.93449 1983 21.59293 1984 21.09347 1985 20.46323 1986 20.08479 1987 19.44183 1988 17.28472 1989 17.02821 1990 17.09013 1991 16.69824 1992 16.33467 1993 15.91873 1994 15.89155 1995 15.84272 1996 15.78328 1997 15.66008 1998 15.17221 1999 15.29917 2000 16.03566 2001 16.41376 2002 16.57119 2003 16.61149 2004 16.77128 2005 17.64903 2006 18.06271 2007 20.15511 2008 20.55255 2009 22.69022 2010 25.15346 2011 27.37082 2012 25.05411 2013 27.32088 2014 29.57616 2015 24.51327 2016 24.34204