Year per 100,000 population 2000 22 2001 22.3 2002 20.9 2003 21.5 2004 20.2 2005 20.7 2006 20.2 2007 18.7 2008 20.3 2009 20.6 2010 20.5 2011 21.1 2012 20.8 2013 19.5 2014 19.4 2015 18.6 2016 19.3 2017 18.9 2018 18.7 2019 18.3