Year % 1998 5.08 1999 4.97 2000 4.53 2001 4.43 2002 4.71 2003 5.09 2004 6.14 2005 6.01 2006 5.74 2007 6.35 2008 6.01 2009 6.19 2010 8.03 2011 7.07 2012 7.51 2013 8.18 2016 10.8