Year	Number of
1990	414.78
1991	413.65
1992	411.34
1993	431.71
1994	459.52
1995	485.09
1996	515.94
1997	518.31
1998	526.84
1999	533.7
2000	533.09
2001	521.38
2002	508.77
2003	512.14
2004	520.36
2005	529.83
2006	535.59
2007	546.87
2008	561.4
2009	562.8
2010	573.46
2011	576.95
2012	576.67
2013	583.86
2014	590.92
2015	600.12
2016	606.8