Year	Number of
1990	180.43
1991	179.49
1992	177.77
1993	174.29
1994	168.26
1995	165.41
1996	163.76
1997	160.4
1998	157.91
1999	153
2000	148.65
2001	146.77
2002	145.74
2003	144.36
2004	141.26
2005	140.4
2006	139.81
2007	138.21
2008	136.83
2009	134.5
2010	132.98
2011	130.46
2012	129.42
2013	128.23
2014	125.6
2015	124.95
2016	125.62