Year	Number
1996	21.1055278778076
1998	17.5
2000	12.93532371521
2002	16.9154224395752
2003	23.3830852508545
2004	17.7884616851807
2005	26.7942581176758
2006	34.9282302856445
2007	34.9282302856445
2008	35.0961532592773
2009	31.2796211242676
2010	31.7535552978516
2011	32.8638496398926
2012	34.7417831420898
2013	34.7417831420898
2014	31.25
2015	29.5238094329834
2016	31.9047622680664
2017	31.4285717010498
2018	32.3809509277344
2019	29.0476188659668
2020	30.9523811340332
2021	29.5238094329834
2022	25.4716987609863