Year	Number of
1990	424.3
1991	416.9
1992	418.37
1993	442.36
1994	452.79
1995	430.12
1996	368.08
1997	357.94
1998	364.18
1999	344.89
2000	327.21
2001	341.63
2002	328.41
2003	331.11
2004	328.17
2005	333.7
2006	360.07
2007	356.61
2008	351.27
2009	349.51
2010	341.87
2011	337.75
2012	326.69
2013	337.83
2014	322.77
2015	319.81
2016	321.43