Year	Number of
1990	478.86
1991	473.57
1992	490.14
1993	505.2
1994	531.2
1995	524.51
1996	507.16
1997	483.65
1998	458.67
1999	441.07
2000	428.74
2001	423.41
2002	424.92
2003	427.68
2004	432.22
2005	447.45
2006	457.54
2007	464.41
2008	453.62
2009	444.99
2010	437.56
2011	439.16
2012	436.81
2013	432.52
2014	429.6
2015	427.68
2016	426.1