Year Percent 1984 11.59083 1985 9.20561 1986 10.63728 1987 11.53753 1988 13.54737 1989 20.21478 1990 8.5956 1991 6.17574 1992 4.77756 1993 8.3146 1994 4.94721 1995 7.60179 1996 8.05869 1997 6.33773 1998 6.30705 1999 9.46837 2000 7.95308 2001 8.98655 2002 19.69755 2003 22.05765 2004 22.9247 2005 17.77675 2006 16.66816 2007 16.08065 2008 14.30718 2009 15.40204 2010 13.07656 2011 12.83908 2012 9.15078 2013 11.04587 2014 11.30538 2015 11.32567 2016 12.8684