Year Percent 1986 -4.029 1987 5.823 1988 -2.57442 1989 7.26278 1990 6.28991 1991 99.63351 1992 574.01451 1993 1207.21105 1994 221.04771 1995 346.00032 1996 430.55281 1997 65.23068 1998 87.82765 1999 26.50724 2000 22.66785 2001 30.20817 2002 18.81846 2003 26.99111 2004 17.51852 2005 9.51573 2006 21.06351 2007 27.23701 2008 28.16376 2009 12.23425 2010 12.46167 2011 13.32436 2012 11.86852 2013 4.34698 2014 5.46374 2015 0.1243 2016 5.27584 2017 4.72252