Year % 1992 12.09 1993 8.86 1996 5.57 1997 4.76 1998 4.14 1999 3.4 2000 2.82 2001 3.35 2002 3.76 2003 4.12 2004 4.35 2005 3.46 2006 3.32 2007 3.41 2008 2.48 2009 2.15 2010 2.28 2011 2.65 2012 2.9 2013 1.79 2014 1.65 2015 1.57 2016 1.5 2017 1.56 2019 1.02 2020 0.91 2021 0.92