Year	Number
1996	21.608039855957
1998	23
2000	24.8756217956543
2002	12.93532371521
2003	18.9054718017578
2004	16.3461532592773
2005	10.5263156890869
2006	10.0478467941284
2007	16.7464122772217
2008	19.230770111084
2009	13.7440757751465
2010	10.4265403747559
2011	9.38967132568359
2012	12.6760559082031
2013	15.023473739624
2014	17.3076915740967
2015	17.619047164917
2016	18.5714282989502
2017	19.0476188659668
2018	19.5238094329834
2019	21.9047622680664
2020	20.4761905670166
2021	25.238094329834
2022	28.301887512207