Year	Number
1996	18.0904521942139
1998	17.5
2000	23.3830852508545
2002	18.4079608917236
2003	19.9004974365234
2004	20.6730766296387
2005	22.0095691680908
2006	22.4880390167236
2007	17.2248802185059
2008	16.3461532592773
2009	16.5876770019531
2010	18.0094795227051
2011	19.2488269805908
2012	23.9436626434326
2013	30.046947479248
2014	38.9423065185547
2015	36.6666679382324
2016	35.238094329834
2017	37.1428565979004
2018	36.6666679382324
2019	35.7142868041992
2020	30.4761905670166
2021	37.1428565979004
2022	40.5660362243652