Year Percent 1981 -2.17736 1982 -0.01769 1983 -0.01675 1984 -0.02835 1985 0.3512 1986 -2.378 1987 0.00003 1988 0 1989 0 1990 -0.46871 1991 38.56834 1992 249.68344 1993 114.83565 1994 38.41649 1995 5.57331 1996 41.27559 1997 12.08871 1998 8.43237 1999 1.53333 2000 3.98129 2001 3.32885 2002 2.41059 2003 5.37972 2004 2.35708 2005 2.62102 2006 2.69605 2007 3.57619 2008 7.63032 2009 2.42005 2010 4.48992 2011 2.31004 2012 1.03999 2013 0.28997 2014 1.55 2015 0.56399 2016 -0.4814 2017 1.37489