Year	Number of
1990	258.51
1991	270.3
1992	282.04
1993	294.87
1994	298.97
1995	310.95
1996	323.38
1997	342.63
1998	360.27
1999	369.9
2000	378.16
2001	387.86
2002	399.69
2003	417.63
2004	421.53
2005	423.88
2006	434.77
2007	442.07
2008	446.45
2009	457.02
2010	459.19
2011	455.19
2012	461.96
2013	467.86
2014	458.48
2015	475.96
2016	481.15