Year	Number of
1990	237.61
1991	247.52
1992	258.57
1993	265.62
1994	283.94
1995	290.85
1996	302.17
1997	313.91
1998	328.56
1999	348.73
2000	359.42
2001	374.92
2002	386.23
2003	397.32
2004	417
2005	434.8
2006	452.14
2007	468.3
2008	487.92
2009	505.92
2010	525.27
2011	546.03
2012	568.82
2013	594.51
2014	620.64
2015	650.15
2016	673.95