Year	per 1,000
1990	0.9
1991	1
1992	1
1993	1
1994	1
1995	1
1996	1
1997	1
1998	1
1999	1
2000	1
2001	1
2002	1
2003	1.1
2004	1.1
2005	1.1
2006	1.1
2007	1.1
2008	1.1
2009	3.8
2010	1.1
2011	1.1
2012	1.1
2013	1.1
2014	1.1
2015	1.2
2016	1.1
2017	1.1
2018	1.1
2019	1.1
2020	1.1
2021	1.1
2022	1