Year	Number
1996	21
1998	23.8805961608887
2000	19.4029846191406
2002	21.8905467987061
2003	27.3631839752197
2004	25.9615383148193
2005	29.3269233703613
2006	32.6923065185547
2007	33.1730766296387
2008	31.25
2009	30.8056869506836
2010	30.8056869506836
2011	30.9859161376953
2012	31.9248828887939
2013	29.577465057373
2014	30.0492610931396
2015	29.0640392303467
2016	28.5714282989502
2017	31.0344829559326
2018	28.6407775878906
2019	28.9855079650879
2020	29.468599319458
2021	25.6038646697998
2022	26.0869560241699