Year % 1998 1.14 1999 1.11 2000 0.95 2001 1.29 2002 1.45 2003 1.69 2004 1.16 2005 1.27 2006 2.93 2007 2.88 2008 2.46 2009 2.68 2010 3.37 2011 2.66 2012 2.57 2013 2.5 2014 2.94 2015 3.55 2016 3.05 2017 2.97 2018 2.62 2019 2.1 2020 1.22 2021 1.53