Year	Number
1996	16.582914352417
1998	18.5
2000	12.4378108978271
2002	16.9154224395752
2003	16.9154224395752
2004	17.7884616851807
2005	21.5311012268066
2006	26.7942581176758
2007	29.6650714874268
2008	32.6923065185547
2009	32.7014236450195
2010	35.5450248718262
2011	41.3145523071289
2012	34.7417831420898
2013	33.8028182983398
2014	35.0961532592773
2015	37.1428565979004
2016	31.9047622680664
2017	30.4761905670166
2018	28.0952377319336
2019	27.1428565979004
2020	23.8095245361328
2021	24.2857151031494
2022	24.5283012390137