Year % 2001 16.560749900888332 2002 18.123771977364825 2003 13.341575588332429 2004 16.741572887872593 2005 18.002896725357935 2006 17.617572656611785 2007 19.35570520853896 2008 15.679550101404265 2009 17.54598279304228 2010 14.687824680093726 2011 15.930275104643796 2012 18.18874492743073 2013 18.655126123724173 2014 15.650522638696188 2015 18.19101872279075 2016 20.98257082814794 2017 22.505981704848395 2018 19.151237796601972 2019 21.332758231991512 2020 18.664986665697565 2021 19.68823850966662 2022 17.46075205858267 2023 15.682594115079937