Year	Number of
1990	264.39
1991	259.13
1992	262.66
1993	283.87
1994	291.91
1995	276.08
1996	234.99
1997	226.12
1998	233.98
1999	228.23
2000	222.82
2001	233.34
2002	226.57
2003	233.09
2004	233.14
2005	233.22
2006	243.03
2007	232.22
2008	213.85
2009	201.81
2010	192.35
2011	183.76
2012	172.88
2013	178.79
2014	167.7
2015	163.54
2016	160.75