Year	Number
1996	6.91489362716675
1998	6.38297891616821
2000	8.99470901489258
2002	5.29100513458252
2003	4.02010059356689
2004	4.85436916351318
2005	7.76699018478394
2006	8.69565200805664
2007	8.69565200805664
2008	9.61538505554199
2009	5.21327018737793
2010	4.7393364906311
2011	5.21327018737793
2012	6.16113758087158
2013	7.5829381942749
2014	8.5714282989502
2015	9.0476188659668
2016	10.4761905670166
2017	11.9047622680664
2018	9.90566062927246
2019	11.7924528121948
2020	11.3207550048828
2021	13.6792449951172
2022	15.5660381317139