Year	Number of
1990	4295.85
1991	4466.75
1992	4643.33
1993	4832.81
1994	5052.67
1995	5468.75
1996	5743.89
1997	6082.55
1998	6488.33
1999	6961.31
2000	7663.67
2001	8155.38
2002	8688.09
2003	9279.08
2004	9935.84
2005	10698.09
2006	11195.33
2007	11720.11
2008	12289.26
2009	12889.44
2010	13514.75
2011	13912.07
2012	14321.61
2013	14743.11
2014	15160.24
2015	15573.87
2016	15995.43