Year	Number of
1990	145.52
1991	152.5
1992	159.86
1993	167.64
1994	175.66
1995	183.94
1996	194.4
1997	205.13
1998	216.29
1999	228.11
2000	240.85
2001	252.51
2002	264.83
2003	278.05
2004	291.99
2005	306.79
2006	318.11
2007	329.78
2008	342.47
2009	355.92
2010	370.3
2011	382.3
2012	394.84
2013	407.28
2014	420.69
2015	435.28
2016	452.94