Year	Number of
2000	24
2001	23
2002	21
2003	21
2004	19
2005	18
2006	18
2007	19
2008	18
2009	17
2010	18
2011	18
2012	20
2013	18
2014	18
2015	19
2016	20
2017	19
2018	19
2019	20
2020	20