Year	Number of
1990	648.25
1991	640.09
1992	631.37
1993	609.98
1994	591.38
1995	575.48
1996	556.87
1997	542.41
1998	522.6
1999	511.93
2000	481.38
2001	470.11
2002	459.6
2003	452.76
2004	440.82
2005	430.87
2006	416.11
2007	413.4
2008	406.52
2009	395.55
2010	383.24
2011	373.61
2012	371.56
2013	368.18
2014	366.96
2015	360.6
2016	357.35