Year	Number
1993	2.5152523047036404
1994	3.4630077543000315
1995	3.6821382092838446
1996	3.4545731905712027
1997	5.890245711421238
1998	6.330704494052912
1999	6.563516616585659
2000	5.704374902840282
2001	5.748103890477725
2002	5.626208017682178
2003	5.440139159746745
2004	5.701663031246238
2005	4.862170776116533
2006	5.251689627327086
2007	4.778422867478843
2008	3.9690415939395365
2009	4.30818743928819
2010	4.855456104729809
2011	4.232010398013938
2012	5.043930654773555
2013	5.403031778528454
2014	4.873202203042828
2015	7.037583700631548
2016	6.5435025667264535
2017	6.5748952048540215
2018	6.370557436932667
2019	5.944588170006254
2020	9.164823483895345
2021	7.7505322495890745
2022	6.3365599079602655
2023	6.731176503712202