Year	Number of
1990	111.27
1991	118.68
1992	124.69
1993	131.89
1994	140.92
1995	151.28
1996	168.79
1997	178.19
1998	192.98
1999	191.11
2000	200.08
2001	213.6
2002	224.22
2003	233.51
2004	237.86
2005	250.65
2006	257.84
2007	259.18
2008	258.86
2009	254.22
2010	252.36
2011	259.32
2012	270.79
2013	288.24
2014	305.68
2015	322.79
2016	340.16