Year	Number
2000	0
2001	1
2002	1
2003	2
2004	2
2005	2
2006	1
2007	3
2008	6
2009	6
2010	5
2011	2
2012	1
2013	1
2014	0
2015	6
2016	7
2017	3
2018	2
2019	3
2020	3