Year	Number
1996	18.5
1998	27.8606967926025
2000	20.3980102539063
2002	17.9104480743408
2003	17.9104480743408
2004	18.269229888916
2005	18.269229888916
2006	15.865385055542
2007	15.384614944458
2008	16.8269233703613
2009	15.6398105621338
2010	14.2180099487305
2011	15.023473739624
2012	15.023473739624
2013	14.0845069885254
2014	14.2857141494751
2015	16.2561569213867
2016	13.7931032180786
2017	13.7931032180786
2018	15.0485439300537
2019	14.4927539825439
2020	15.9420289993286
2021	18.8405799865723
2022	19.8067626953125