Year	Number
1996	9.04522609710693
1998	8
2000	11.4427862167358
2002	8.95522403717041
2003	10.945273399353
2004	13.942307472229
2005	13.8755979537964
2006	11.4832534790039
2007	10.5263156890869
2008	9.13461494445801
2009	9.00473976135254
2010	10.9004735946655
2011	12.6760559082031
2012	15.023473739624
2013	18.3098583221436
2014	30.769229888916
2015	27.1428565979004
2016	25.238094329834
2017	28.0952377319336
2018	27.1428565979004
2019	24.761905670166
2020	21.9047622680664
2021	27.619047164917
2022	30.1886787414551