Year	Number
1996	21.608039855957
1998	18.5
2000	21.8905467987061
2002	16.9154224395752
2003	18.4079608917236
2004	17.7884616851807
2005	19.1387557983398
2006	23.9234447479248
2007	21.0526313781738
2008	19.230770111084
2009	14.2180099487305
2010	12.3222751617432
2011	15.023473739624
2012	16.9014091491699
2013	24.4131450653076
2014	29.8076915740967
2015	23.3333339691162
2016	27.1428565979004
2017	26.6666660308838
2018	29.0476188659668
2019	29.5238094329834
2020	37.1428565979004
2021	39.0476188659668
2022	39.1509437561035