Year	Number of
1990	173.8
1991	182.99
1992	193.45
1993	205.15
1994	217.89
1995	231.96
1996	250.22
1997	270.07
1998	291.99
1999	316.54
2000	344.4
2001	370.26
2002	399.29
2003	431.87
2004	468.07
2005	508.31
2006	552.55
2007	601.27
2008	654.39
2009	711.21
2010	771.56
2011	823.79
2012	877.2
2013	932.27
2014	991.1
2015	1055.43
2016	1126.64