Year	Number of
1990	3863.16
1991	4063.61
1992	4265.43
1993	4439.19
1994	4591.12
1995	4728.05
1996	4923.52
1997	5006.73
1998	5172.19
1999	5314.32
2000	5434.13
2001	5593.4
2002	5734.85
2003	5922.94
2004	6091.12
2005	6221.87
2006	6333.08
2007	6449.16
2008	6515.08
2009	6578.04
2010	6580.71
2011	6602.22
2012	6660.56
2013	6700.93
2014	6768.14
2015	6871.04
2016	6989.93