Year	Number
1996	21.2765960693359
1998	34.5744667053223
2000	26.4550266265869
2002	23.8095245361328
2003	21.608039855957
2004	21.8446598052979
2005	17.4757289886475
2006	19.8067626953125
2007	18.3574886322021
2008	15.865385055542
2009	19.9052124023438
2010	22.274881362915
2011	20.3791465759277
2012	20.3791465759277
2013	19.4312801361084
2014	20.9523811340332
2015	21.9047622680664
2016	22.8571434020996
2017	20.4761905670166
2018	21.2264156341553
2019	20.2830181121826
2020	20.2830181121826
2021	18.8679237365723
2022	20.7547168731689