Year	Number
1996	11
1998	6.96517419815063
2000	5.47263669967651
2002	5.47263669967651
2003	5.97014904022217
2004	7.21153831481934
2005	7.21153831481934
2006	4.807692527771
2007	4.32692289352417
2008	4.807692527771
2009	5.68720388412476
2010	4.7393364906311
2011	3.75586843490601
2012	3.28638505935669
2013	3.28638505935669
2014	3.44827580451965
2015	2.95566511154175
2016	1.47783255577087
2017	1.97044336795807
2018	1.94174754619598
2019	1.44927537441254
2020	1.44927537441254
2021	0.966183602809906
2022	0.966183602809906