Year	Number
2000	20
2001	20
2002	20
2003	22
2004	20
2005	21
2006	20
2007	20
2008	21
2009	20
2010	19
2011	19
2012	19
2013	18
2014	17
2015	16
2016	16
2017	15
2018	15
2019	11
2020	12