Year	Number
1996	25
1998	17.9104480743408
2000	21.8905467987061
2002	13.9303483963013
2003	11.9402980804443
2004	18.269229888916
2005	13.942307472229
2006	9.13461494445801
2007	10.0961542129517
2008	12.0192308425903
2009	11.3744077682495
2010	12.3222751617432
2011	12.6760559082031
2012	14.5539903640747
2013	15.023473739624
2014	14.7783250808716
2015	16.2561569213867
2016	14.7783250808716
2017	14.2857141494751
2018	13.1067962646484
2019	15.9420289993286
2020	16.425121307373
2021	19.8067626953125
2022	18.8405799865723