Year	Number
1996	21.2765960693359
1998	30.319149017334
2000	37.037036895752
2002	40.2116394042969
2003	26.6331653594971
2004	27.6699028015137
2005	31.0679607391357
2006	26.57004737854
2007	29.468599319458
2008	29.8076915740967
2009	30.8056869506836
2010	33.1753540039063
2011	36.4928894042969
2012	40.2843589782715
2013	33.6492881774902
2014	30.9523811340332
2015	33.3333320617676
2016	29.0476188659668
2017	25.238094329834
2018	19.8113212585449
2019	27.3584899902344
2020	26.8867931365967
2021	28.7735843658447
2022	25.4716987609863