Year	Number
1990	17
1991	17
1992	17
1993	17
1994	16
1995	16
1996	17
1997	17
1998	17
1999	16
2000	16
2001	16
2002	17
2003	17
2004	17
2005	17
2006	16
2007	16
2008	15
2009	15
2010	15
2011	15
2012	15
2013	15
2014	15
2015	15
2016	15
2017	15
2018	15
2019	15
2020	15
2021	15
2022	14