Year	Number
1996	22.1105518341064
1998	18.5
2000	14.4278602600098
2002	17.9104480743408
2003	22.8855724334717
2004	15.865385055542
2005	22.4880390167236
2006	15.7894735336304
2007	13.3971290588379
2008	13.942307472229
2009	16.5876770019531
2010	14.2180099487305
2011	17.3708915710449
2012	16.9014091491699
2013	19.2488269805908
2014	14.9038457870483
2015	13.3333330154419
2016	17.619047164917
2017	18.0952377319336
2018	7.14285707473755
2019	5.7142858505249
2020	5.2380952835083
2021	4.7619047164917
2022	5.18867921829224