Year	Number of
1990	1000.57
1991	1033.23
1992	1066.16
1993	1098.45
1994	1112.28
1995	1146.53
1996	1156.17
1997	1162.01
1998	1156.92
1999	1134.1
2000	1122.39
2001	1108.32
2002	1137.92
2003	1115.75
2004	1105.89
2005	1076.4
2006	1056.13
2007	1051.88
2008	1007.07
2009	991.12
2010	967.14
2011	942.38
2012	935.81
2013	945.56
2014	956.84
2015	992.09
2016	1030.71