Year	Number of
1990	497.85
1991	511.39
1992	512.16
1993	514.87
1994	524.75
1995	541.85
1996	548.06
1997	551.67
1998	549.69
1999	558.41
2000	558.96
2001	558.8
2002	566.25
2003	573.83
2004	595.26
2005	623.46
2006	635.69
2007	652.64
2008	661.51
2009	670.58
2010	683.79
2011	688.53
2012	690.7
2013	690.56
2014	687.84
2015	691.92
2016	696.03