Year	Number of
1990	126.61
1991	131.41
1992	136.63
1993	142.13
1994	148.21
1995	154.97
1996	161.4
1997	168.32
1998	175.74
1999	183.41
2000	191.29
2001	194.01
2002	197.05
2003	200.36
2004	203.86
2005	207.62
2006	217.67
2007	228.46
2008	240.24
2009	253.39
2010	268.14
2011	277.13
2012	287.19
2013	297.62
2014	308.58
2015	319.91
2016	331.31