Year	Number of
1990	301.19
1991	305.06
1992	287.59
1993	275.54
1994	271.68
1995	269.73
1996	261.91
1997	252.27
1998	243.44
1999	229.16
2000	215.41
2001	206.37
2002	202.37
2003	197.38
2004	193.86
2005	187.94
2006	182.61
2007	183.25
2008	178.93
2009	176.12
2010	178.59
2011	176.5
2012	173.34
2013	170.48
2014	168.42
2015	170.85
2016	172.22