Year	Number of
1990	211.67
1991	222.81
1992	230.49
1993	238.37
1994	247.04
1995	252.47
1996	265.15
1997	278.26
1998	287.21
1999	300.19
2000	313.08
2001	322.14
2002	327.33
2003	329.74
2004	328.74
2005	329.37
2006	329.54
2007	335.98
2008	339.13
2009	340.39
2010	340.69
2011	338.27
2012	342.07
2013	358.94
2014	357.3
2015	354.68
2016	355.83