Year	per 100,000 population
2000	20.8
2001	19.7
2002	19.5
2003	19.7
2004	20.2
2005	20.1
2006	18.3
2007	18.1
2008	18.4
2009	18.3
2010	18.3
2011	16.4
2012	18.4
2013	16.5
2014	17.3
2015	17.6
2016	16.4
2017	15.7
2018	16.4
2019	16.4