Year Percent 1995 0.17871 1996 1.17251 1997 2.85047 1998 0.38018 1999 1.80938 2000 1.62387 2001 4.01046 2002 2.53557 2003 2.79527 2004 3.22473 2005 6.23678 2006 9.05798 2007 11.0252 2008 5.18577 2009 6.93219 2010 6.37054 2011 -5.90994 2012 5.56313 2013 3.38621 2014 4.32973 2015 -2.54394 2016 1.6805 2017 2.161