Year	Number of
1990	210.85
1991	213.44
1992	216.68
1993	222.57
1994	225.95
1995	229.32
1996	233.47
1997	236.8
1998	240.64
1999	244
2000	248.33
2001	252.84
2002	258.45
2003	265.53
2004	272.12
2005	279.3
2006	286.74
2007	294.65
2008	305.11
2009	317.2
2010	330.36
2011	342.58
2012	356.05
2013	369.98
2014	385.19
2015	401.69
2016	419