Year	Number of
1990	340.13
1991	343.48
1992	349.44
1993	360.74
1994	377.08
1995	397.54
1996	407.52
1997	409.85
1998	410.06
1999	408.44
2000	408.63
2001	415.15
2002	430.29
2003	438.76
2004	442.32
2005	443.2
2006	438.92
2007	429.62
2008	422.03
2009	423.12
2010	428.33
2011	436.84
2012	441.13
2013	443.65
2014	446.77
2015	465.87
2016	487.6