Year	per 100,000 population
2000	21.4
2001	21.9
2002	22.1
2003	21.1
2004	20.5
2005	20.8
2006	20.7
2007	20.9
2008	20.5
2009	20.5
2010	20.3
2011	20.7
2012	20.3
2013	19.6
2014	18.8
2015	18.3
2016	18
2017	17.8
2018	17.6
2019	17.4