Year	Number of
1990	242.24
1991	257.7
1992	279.01
1993	303.05
1994	327.41
1995	357.56
1996	365.71
1997	369.26
1998	378.64
1999	384.28
2000	392.16
2001	393.33
2002	392.13
2003	392.56
2004	398.3
2005	396.31
2006	404.6
2007	408.69
2008	415.49
2009	423.76
2010	434.7
2011	446.85
2012	461.41
2013	473.97
2014	485.65
2015	496.72
2016	507.75