Year % 1995 2.71 1997 2.67 2002 1.73 2006 1.42 2007 1.57 2008 1.55 2009 1.75 2010 2.46 2011 1.42 2012 1.49 2013 1.68 2014 1.73 2015 1.39 2016 1.38 2017 1.53 2018 1.66 2019 23.7 2020 2.55 2021 3.11