Year	Number of
1990	3519.51
1991	3536.97
1992	3551.07
1993	3559.57
1994	3571.54
1995	3596.88
1996	3574.97
1997	3552.47
1998	3532.1
1999	3509.64
2000	3481.42
2001	3496.78
2002	3505.27
2003	3510.54
2004	3523.61
2005	3551.34
2006	3584.65
2007	3618.57
2008	3652.03
2009	3689.37
2010	3735.68
2011	3793.34
2012	3839.84
2013	3883.44
2014	3937.28
2015	3988.4
2016	4047.1