Year	Number
1985	13200
1989	8000
1990	8000
1991	8000
1992	8000
1993	8000
1994	8000
1995	16200
1996	16200
1997	15400
1998	15400
1999	15400
2000	15400
2001	21900
2002	25900
2003	17000
2006	10000
2007	10000
2008	10000
2009	9800
2010	9800
2011	9800
2012	9800
2013	9800
2014	9800
2015	9800
2016	9800
2017	10000
2018	10000
2019	10000
2020	10000