Year Percent 1976 0.2736 1977 0.19303 1978 0.32732 1979 0.11027 1980 0.6694 1981 1.54014 1982 1.13323 1983 -0.85872 1984 0.48547 1985 0.80276 1986 0.21626 1987 0.04413 1988 -0.246 1989 -0.49029 1990 0.34748 1991 0.27123 1992 -0.18679 1993 0.00345 1994 -0.02181 1995 -0.13268 1996 1.13713 1997 1.95811 1998 1.77142 1999 0.73343 2000 1.73808 2001 2.00884 2002 0.99814 2003 2.96343 2004 5.50409 2005 18.53448 2006 22.7382 2007 32.23352 2008 6.81651 2009 0.49125 2010 1.93067 2011 7.51363 2012 7.16605 2013 3.0396 2014 4.4312 2015 6.76278 2016 -5.25158 2017 -29.3746