Year	Number of
1990	96.52
1991	102.79
1992	108.14
1993	113.42
1994	119.13
1995	124.95
1996	128.81
1997	132.92
1998	137.65
1999	142.59
2000	147.75
2001	153.89
2002	160.58
2003	168.03
2004	175.55
2005	183.19
2006	187.83
2007	192.54
2008	197.97
2009	203.96
2010	210.3
2011	216.91
2012	224.28
2013	231.83
2014	240.53
2015	249.86
2016	259.12