Year	Number of
1990	236.5
1991	242.82
1992	229.16
1993	239.67
1994	247.75
1995	226.99
1996	206.81
1997	200.16
1998	209.39
1999	195.14
2000	192.93
2001	188.69
2002	180.44
2003	177.57
2004	169.05
2005	168.75
2006	166.93
2007	163.7
2008	155.43
2009	150.74
2010	136.4
2011	136.51
2012	134.87
2013	136.68
2014	135.98
2015	134.88
2016	134.79