Year	Number of
1990	1270.65
1991	1280.09
1992	1280.78
1993	1259.14
1994	1255.79
1995	1253.34
1996	1250.35
1997	1247.3
1998	1228.97
1999	1218.43
2000	1209.26
2001	1186.01
2002	1160.95
2003	1154.22
2004	1146.81
2005	1154.26
2006	1134.67
2007	1139.1
2008	1138.28
2009	1119.38
2010	1088.72
2011	1053.22
2012	1003.79
2013	909.3
2014	986.27
2015	1016.31
2016	1039.4