Year	Number of
1990	149.77
1991	158.15
1992	166.51
1993	175.2
1994	184.56
1995	194.86
1996	202.37
1997	210.33
1998	218.75
1999	227.25
2000	235.74
2001	244.25
2002	252.44
2003	260.6
2004	268.99
2005	277.94
2006	288.66
2007	299.74
2008	311.94
2009	325
2010	339.18
2011	352.28
2012	366.99
2013	382.88
2014	399.59
2015	416.99
2016	436.32