Year % 1993 5.13 1996 2.87 1998 2.74 1999 2.79 2000 2.87 2001 3.16 2003 2.97 2004 2.78 2005 2.6 2006 2.36 2007 2.49 2008 2.62 2009 2.66 2010 2.7 2011 2.53 2012 2.39 2013 2.56 2014 2.47 2015 2.35 2016 1.72 2017 0 2019 0 2021 0