Year	Number
1996	12
1998	6.96517419815063
2000	7.46268653869629
2002	3.98009943962097
2003	8.4577112197876
2004	6.73076915740967
2005	7.21153831481934
2006	8.65384578704834
2007	10.5769233703613
2008	13.4615383148193
2009	13.7440757751465
2010	13.7440757751465
2011	15.4929580688477
2012	14.5539903640747
2013	15.962441444397
2014	21.1822662353516
2015	22.660099029541
2016	25.6157627105713
2017	23.645320892334
2018	21.3592224121094
2019	22.2222213745117
2020	21.7391300201416
2021	20.7729473114014
2022	21.7391300201416