Year Percent 1981 6.61244 1982 0.85939 1983 7.32469 1984 1.76092 1985 6.68627 1986 1.22838 1987 2.79689 1988 4.46062 1989 3.95946 1990 -1.28083 1991 -0.92888 1992 8.10898 1993 5.78479 1994 15.99464 1995 11.28507 1996 8.65314 1997 8.5589 1998 10.05083 1999 8.88436 2000 11.97489 2001 0.2417 2002 3.29769 2003 2.35579 2004 8.42582 2005 5.35732 2006 6.58498 2007 13.83463 2008 5.50425 2009 -2.31143 2010 0.37191 2011 2.80594 2012 -0.08077 2013 -0.38469 2014 -0.59875 2015 -0.22058 2016 2.53851 2017 2.59305