Year	Number of
1990	356.11
1991	354.69
1992	394.1
1993	401.35
1994	396.7
1995	426.68
1996	466.38
1997	478.04
1998	507.02
1999	509.87
2000	498.94
2001	504.43
2002	490.62
2003	497.62
2004	491.02
2005	503.13
2006	504.46
2007	493.48
2008	507.09
2009	503.9
2010	502.98
2011	491.56
2012	490.65
2013	467.22
2014	461.27
2015	491.36
2016	487.97