Year	Number of
2000	2
2001	1
2002	2
2003	2
2004	1
2005	1
2006	1
2007	4
2008	4
2009	3
2010	3
2011	2
2012	3
2013	4
2014	2
2015	3
2016	3
2017	3
2018	3
2019	3
2020	3