Year	per 1,000 people
1991	19.8999996185
2000	6.29
2001	6.04
2002	5.95
2003	5.82
2004	5.67
2005	5.54
2006	5.39
2007	5.36
2008	5.21
2009	5.1
2010	5.19
2011	5.05
2012	4.97
2013	4.85
2014	4.73
2015	4.73
2016	4.69
2017	4.65
2018	4.63