Year	Number of
1990	338.77
1991	350.7
1992	362.3
1993	374.56
1994	386.76
1995	398.87
1996	408.49
1997	416.7
1998	424.38
1999	426.67
2000	430.69
2001	434.44
2002	441.17
2003	452.04
2004	466.86
2005	490.11
2006	487.79
2007	495.55
2008	509.41
2009	528.35
2010	552.61
2011	568.03
2012	593.94
2013	609.18
2014	640.3
2015	665.79
2016	687.08