Year	per 1,000 people
2004	10.4
2005	9.5
2006	10
2007	9.4
2008	11
2009	10.7
2010	10.3
2011	10
2012	8.7
2013	9.7
2014	9.1
2015	8.2
2016	7.9
2017	6.7
2018	6.8
2019	6.7
2020	6.4
2021	6.2
2022	6.1