Year	Number of
1990	97.56
1991	101.63
1992	105.97
1993	110.55
1994	115.59
1995	121.33
1996	124.53
1997	128.35
1998	132.6
1999	137.25
2000	142.47
2001	145.87
2002	149.38
2003	153.2
2004	157.25
2005	161.85
2006	165.51
2007	169.17
2008	173.6
2009	178.3
2010	183.54
2011	187.78
2012	192.79
2013	198.21
2014	203.96
2015	210
2016	216.44