Year	Number of
1990	695.98
1991	693.86
1992	690.85
1993	683.93
1994	674.73
1995	663.77
1996	661.36
1997	646.71
1998	625.35
1999	621.21
2000	611.37
2001	607.81
2002	592.95
2003	577.83
2004	578.72
2005	577.47
2006	575.8
2007	568.69
2008	560.61
2009	553.18
2010	542.73
2011	535.85
2012	531.53
2013	523.77
2014	523.68
2015	522.98
2016	520.36