Year	Number
1975	1200
1976	1500
1977	1500
1978	1600
1979	1600
1981	1200
1982	1200
1983	1200
1984	1200
1985	1200
1986	1200
1987	1200
1988	1180
1989	1200
1990	1200
1991	1200
1992	1200
1993	1400
1994	1500
1995	1550
1996	1600
1997	1650
1998	1700
1999	1750
2000	1800
2001	1850
2002	1800
2003	1800
2004	1800
2005	1800
2006	1800
2007	1800
2008	1800
2009	1900
2010	0
2011	0
2012	0
2013	0
2014	0
2015	0
2016	0
2017	0
2018	0
2019	0