Year	per 1,000
1990	1.6302518011891378
1991	1.5756096531347696
1992	1.545850111214744
1993	1.497173542507688
1994	1.463109739795388
1995	1.4459618045622695
1996	1.3795836110926838
1997	1.4207905740458167
1998	1.4794680690290232
1999	1.470888995358624
2000	1.4904106799290435
2001	1.4515397296197268
2002	1.3170351413291541
2003	1.179720086717919
2004	1.0897788262160368
2005	1.0209404330888374
2006	0.9863575893713092
2007	0.9820251225207116
2008	0.9347083698011344
2009	0.9228420448369578
2010	0.9015771046258748
2011	0.8641109482141065
2012	0.8280558925662793
2013	0.8199339542399511
2014	0.799930283496334
2015	0.733996537656527
2016	0.7265377105395865
2017	0.7249595633559189
2018	0.6925425489919749
2019	0.6786046004743949
2020	0.6593527298909353
2021	0.653696677247328
2022	0.6376794980295284