Year	Number of
1990	92.59
1991	94.87
1992	97.2
1993	99.93
1994	103.75
1995	106.21
1996	112.08
1997	117.44
1998	122.95
1999	130.55
2000	137.97
2001	141.78
2002	146.32
2003	150.77
2004	156.9
2005	160.65
2006	166.14
2007	172.49
2008	179.53
2009	186.89
2010	194.62
2011	201.91
2012	209
2013	215.44
2014	223.2
2015	231.7
2016	240.22