Year	Number of
1990	63.96
1991	64.49
1992	66.33
1993	68.35
1994	71.06
1995	71.84
1996	71.74
1997	71.81
1998	79.08
1999	83.85
2000	97.95
2001	97.82
2002	101.7
2003	111
2004	111.93
2005	114.31
2006	113.27
2007	115.63
2008	123.09
2009	123.71
2010	128.5
2011	126.44
2012	128.22
2013	130.83
2014	130.24
2015	129.19
2016	126.83