Year	Number
1996	21.5
1998	27.8606967926025
2000	26.8656711578369
2002	19.9004974365234
2003	22.3880596160889
2004	19.230770111084
2005	22.5961532592773
2006	20.1923084259033
2007	15.384614944458
2008	13.4615383148193
2009	15.1658763885498
2010	28.4360198974609
2011	28.6384983062744
2012	24.8826293945313
2013	24.4131450653076
2014	28.5714282989502
2015	28.0788173675537
2016	31.0344829559326
2017	32.019702911377
2018	30.5825233459473
2019	30.4347820281982
2020	28.9855079650879
2021	26.57004737854
2022	24.1545886993408