Year	Number
1996	22.1105518341064
1998	24.5
2000	27.8606967926025
2002	24.3781089782715
2003	24.8756217956543
2004	19.7115383148193
2005	18.1818180084229
2006	18.1818180084229
2007	21.0526313781738
2008	20.1923084259033
2009	19.9052124023438
2010	21.3270149230957
2011	23.474178314209
2012	26.7605628967285
2013	24.8826293945313
2014	27.4038467407227
2015	27.1428565979004
2016	21.9047622680664
2017	21.4285717010498
2018	19.0476188659668
2019	24.761905670166
2020	24.2857151031494
2021	27.619047164917
2022	29.7169818878174