Year	Number of
1990	187.36
1991	197.06
1992	207.43
1993	218.76
1994	230.31
1995	242.39
1996	251.79
1997	262.38
1998	271.79
1999	281.81
2000	292.64
2001	303.26
2002	314.4
2003	326.64
2004	340
2005	354.94
2006	363.73
2007	373.28
2008	384.21
2009	396.05
2010	408.96
2011	426.55
2012	445.61
2013	465.66
2014	487.1
2015	510
2016	534.31