Year	Number
1993	3.063532947549996
1994	4.068203709605626
1995	6.451007028352027
1996	5.050904610327554
1997	4.013810542915629
1998	4.815491434887923
1999	4.904334053652244
2000	4.580717327309269
2001	4.465763492840333
2002	6.40560317960465
2003	5.80061149516572
2004	4.45464422861041
2005	3.883461257504154
2006	3.4031434403993477
2007	2.935493173821476
2008	2.6952014677858998
2009	3.785846231740958
2010	3.401115247198303
2011	2.7788601957250076
2012	3.2071580002519267
2013	4.004643047602289
2014	3.6674846427592427
2015	4.897998140395679
2016	6.468225539517467
2017	9.875380425233725
2018	8.52326454757547
2019	9.108261494549835
2020	11.28675391331142
2021	9.26653410829569
2022	6.812203970528549
2023	7.102296816677684