Year	Number of
1990	71.21
1991	71.62
1992	71.78
1993	71.21
1994	73.89
1995	75.83
1996	82.31
1997	87.94
1998	93.64
1999	98.61
2000	105.88
2001	108.58
2002	114.13
2003	114.7
2004	119.84
2005	124.32
2006	130.96
2007	139.58
2008	148.14
2009	157
2010	165.47
2011	172.99
2012	180.34
2013	188.16
2014	195.15
2015	203.13
2016	210.16