Year	Number of
1990	121.83
1991	127.33
1992	132.81
1993	138.57
1994	144.68
1995	150.58
1996	155.89
1997	161.4
1998	166.13
1999	177.75
2000	184.57
2001	190.81
2002	197.95
2003	205.53
2004	215.23
2005	220.01
2006	231.17
2007	240.01
2008	250.98
2009	262.72
2010	275.83
2011	287.3
2012	297.86
2013	309.32
2014	321.22
2015	334.38
2016	348.55