Year	Number of
1990	1359.56
1991	1350.92
1992	1344.99
1993	1329.37
1994	1289.99
1995	1263.64
1996	1238.87
1997	1215.01
1998	1192.23
1999	1184.8
2000	1164.78
2001	1161.99
2002	1158.52
2003	1135.78
2004	1123.07
2005	1108.55
2006	1097.14
2007	1076.81
2008	1065.91
2009	1057.77
2010	1047.69
2011	1018.68
2012	1003.13
2013	982.81
2014	955.9
2015	937.16
2016	927.73