Year	Number
1996	5.411941840140776
1997	5.6792801160008715
1998	6.608152873119348
1999	8.247849818430911
2000	8.795205311446475
2001	10.694240054348034
2002	13.073826410809206
2003	17.064928253565846
2004	17.9567856611529
2005	15.835170191059387
2006	15.018126103433898
2007	15.005023322116568
2008	13.331052411007553
2009	18.384731626649906
2010	15.807013452048421
2011	15.233315561171027
2012	14.234734326361192
2013	14.97187703538701
2014	14.212423200368445
2015	16.80282159066032
2016	16.96897386406908
2017	16.273309373505022
2018	14.68913071945498
2019	15.423352300840524
2020	18.51861660990825
2021	16.07221582748571
2022	12.338417621204917
2023	13.616139780252789