Year	Number of
1990	213.55
1991	218.77
1992	225.77
1993	234.9
1994	244.91
1995	256.12
1996	269.74
1997	284.24
1998	295.53
1999	305.82
2000	314.16
2001	323.27
2002	333.14
2003	342.98
2004	353.34
2005	362.94
2006	371.34
2007	377.94
2008	383.16
2009	386.22
2010	392
2011	402.53
2012	414.7
2013	430.56
2014	447.66
2015	467.84
2016	487.92