Year	Number of
1990	1658.1
1991	1601
1992	1593.74
1993	1587.3
1994	1589.45
1995	1568.05
1996	1496.6
1997	1410.81
1998	1322.39
1999	1274
2000	1232.17
2001	1193.05
2002	1171.02
2003	1161.97
2004	1174.26
2005	1187.18
2006	1179.53
2007	1141.36
2008	1071.3
2009	1026.01
2010	991.95
2011	983.13
2012	960.84
2013	899.48
2014	858.75
2015	838.38
2016	866.84