Year	per 100,000 population
2000	19.6
2001	19.5
2002	19.1
2003	18.5
2004	18.5
2005	18.3
2006	17.8
2007	17.6
2008	17.3
2009	17.9
2010	18
2011	17.7
2012	17
2013	16.8
2014	16.7
2015	16.7
2016	15.7
2017	16.4
2018	20.4
2019	20
