Year Percent 1991 -2.22958 1992 -23.76383 1993 -24.2594 1994 -20.77814 1995 -12.80997 1996 0.28217 1997 4.78428 1998 8.96089 1999 6.46158 2000 10.19103 2001 9.05182 2002 9.7778 2003 10.36068 2004 9.23949 2005 25.11444 2006 33.03049 2007 23.63913 2008 8.47061 2009 7.16254 2010 3.61419 2011 -1.22948 2012 0.85099 2013 4.43707 2014 0.73474 2015 -0.09717 2016 -4.17717 2017 -0.96182