Year	Number of
1990	4167.26
1991	4068.21
1992	4006.36
1993	3957.88
1994	3924.24
1995	3865.26
1996	3779.51
1997	3731.68
1998	3725.22
1999	3688.55
2000	3629.43
2001	3579.72
2002	3537.35
2003	3478.03
2004	3422.43
2005	3395.48
2006	3409.87
2007	3396.03
2008	3438.22
2009	3452.37
2010	3501.79
2011	3524.76
2012	3524
2013	3497.68
2014	3415.15
2015	3375.95
2016	3343.21