Year	Number of
1990	269
1991	247.09
1992	225.53
1993	198.92
1994	189.16
1995	175.7
1996	163.78
1997	153.8
1998	145.3
1999	140.64
2000	137.26
2001	139.43
2002	142.88
2003	146.91
2004	151.23
2005	155.82
2006	155.57
2007	155.97
2008	157.81
2009	161.45
2010	167.9
2011	174.89
2012	174.81
2013	175.31
2014	179.97
2015	186.06
2016	191.33