Year	Number of
1990	110.82
1991	116.36
1992	122.32
1993	128.8
1994	135.73
1995	143.2
1996	149.82
1997	156.84
1998	164.48
1999	172.44
2000	180.8
2001	190.06
2002	199.83
2003	210.35
2004	221.5
2005	233.48
2006	247.2
2007	261.7
2008	277.13
2009	293.52
2010	311.1
2011	327.22
2012	344.55
2013	362.93
2014	382.25
2015	402.48
2016	423.52