Year	Number of
1990	366.99
1991	371.22
1992	375.82
1993	380.7
1994	387.24
1995	399.46
1996	408.32
1997	421.64
1998	433.7
1999	442.21
2000	451.17
2001	456.52
2002	461.59
2003	469.48
2004	479.02
2005	490.9
2006	498.98
2007	508.27
2008	515.64
2009	526.98
2010	539.65
2011	552.16
2012	568.16
2013	583.06
2014	599.39
2015	611.84
2016	626.04