Year	per 100,000 population
2000	20
2001	20
2002	19
2003	17.2
2004	17.5
2005	16.9
2006	17.4
2007	17.9
2008	18
2009	17.7
2010	16.2
2011	15.8
2012	16.7
2013	16.7
2014	16.9
2015	18
2016	18.6
2017	17.2
2018	16.3
2019	15.4