Year	Number of
1990	76.83
1991	80.31
1992	83.99
1993	88
1994	92.28
1995	96.82
1996	100.72
1997	104.42
1998	108.44
1999	112.41
2000	116.25
2001	120.48
2002	125.27
2003	129.86
2004	135.18
2005	140.93
2006	145.96
2007	151.08
2008	156.17
2009	161.4
2010	167.15
2011	173.69
2012	180.65
2013	187.61
2014	195.58
2015	203.97
2016	213.06