Year Percent 1981 2.82094 1982 1.91647 1983 -0.64527 1984 2.73675 1985 0.22918 1986 1.34549 1987 0.06384 1988 -5.38974 1989 6.72968 1990 26.188 1991 226.53786 1992 59.57865 1993 51.09105 1994 72.70497 1995 62.37665 1996 103.43915 1997 958.50323 1998 32.20662 1999 2.44303 2000 7.3108 2001 6.10841 2002 3.77371 2003 2.27115 2004 5.65949 2005 6.51169 2006 6.74144 2007 11.0914 2008 8.12977 2009 4.04742 2010 1.10747 2011 5.97863 2012 1.55524 2013 -0.70289 2014 0.4521 2015 2.20583 2016 2.24622 2017 1.17829