Year	Number
1996	6.03015089035034
1998	7
2000	7.96019887924194
2002	3.98009943962097
2003	3.48258709907532
2004	6.73076915740967
2005	7.17703342437744
2006	14.3540668487549
2007	16.7464122772217
2008	11.5384616851807
2009	17.5355453491211
2010	16.1137447357178
2011	17.3708915710449
2012	16.9014091491699
2013	16.9014091491699
2014	15.384614944458
2015	12.8571424484253
2016	23.3333339691162
2017	22.8571434020996
2018	23.8095245361328
2019	27.1428565979004
2020	30.9523811340332
2021	24.2857151031494
2022	23.5849056243896