Year % 1995 3.36 1997 3.93 2002 3.99 2006 4.13 2007 4.69 2008 4.69 2009 2.47 2010 2.9 2011 2.42 2012 2.57 2013 2.78 2014 2.65 2015 2.46 2016 2.46 2017 2.73 2018 2.73 2019 10.63 2020 3.26 2021 3.5