Year	Number of
1990	4637.55
1991	4783.43
1992	4927.19
1993	5160.38
1994	5395.78
1995	5611.31
1996	6118.21
1997	6318.54
1998	6604.79
1999	6878.15
2000	7152.73
2001	7425.98
2002	7682.65
2003	7952.77
2004	8247.63
2005	8577.26
2006	8885.3
2007	9183.05
2008	9477.25
2009	9855.99
2010	10252.4
2011	10666.85
2012	11078.77
2013	11506.86
2014	11949.61
2015	12401.52
2016	12813.19