Year	Number
1990	11
1991	11
1992	11
1993	12
1994	12
1995	12
1996	13
1997	13
1998	13
1999	14
2000	15
2001	15
2002	15
2003	15
2004	15
2005	15
2006	15
2007	15
2008	15
2009	15
2010	15
2011	15
2012	15
2013	15
2014	13
2015	13
2016	13
2017	12
2018	11
2019	10
2020	10
2021	10
2022	9