Year	Number of
1990	221.93
1991	233.22
1992	245.54
1993	259.65
1994	275.06
1995	291.2
1996	299.87
1997	308.26
1998	318.03
1999	328.08
2000	340.06
2001	353.54
2002	367.72
2003	383.61
2004	400.78
2005	419.13
2006	429.55
2007	441.25
2008	456.64
2009	472.27
2010	489.81
2011	505.59
2012	523.9
2013	542.54
2014	562.49
2015	584.94
2016	606.75