Year	Number of
1990	92.76
1991	98.16
1992	103.08
1993	108.06
1994	113.47
1995	119.25
1996	122.96
1997	127.02
1998	131.68
1999	136.38
2000	141.36
2001	146.92
2002	152.99
2003	159.5
2004	166.46
2005	173.73
2006	177.79
2007	181.99
2008	186.84
2009	192.32
2010	198.26
2011	204.13
2012	210.86
2013	218.09
2014	226.19
2015	234.96
2016	243.69