Year	Number of
1990	255.7
1991	270.08
1992	247.67
1993	255.29
1994	271.41
1995	275.2
1996	256.75
1997	214.68
1998	206.24
1999	210.67
2000	213.39
2001	211.98
2002	210.45
2003	217.81
2004	212.03
2005	226.53
2006	226.74
2007	218.22
2008	210.9
2009	205.73
2010	213.94
2011	182.6
2012	185.37
2013	177.8
2014	185.93
2015	185.73
2016	181.58