Year Number 1996 11.702127456665 1998 15.957447052002 2000 25.9259262084961 2002 30.1587295532227 2003 35.1758804321289 2004 35.4368934631348 2005 30.5825233459473 2006 29.468599319458 2007 42.9951705932617 2008 43.75 2009 28.9099521636963 2010 22.274881362915 2011 23.222749710083 2012 33.6492881774902 2013 19.4312801361084 2014 8.09523773193359 2015 7.61904764175415 2016 13.3333330154419 2017 17.1428565979004 2018 20.7547168731689 2019 22.6415100097656 2020 20.2830181121826 2021 17.9245281219482 2022 17.4528293609619