Year	Number of
1990	117.26
1991	121.26
1992	123.72
1993	126.9
1994	132.27
1995	137.06
1996	142.64
1997	144.24
1998	148.18
1999	153.62
2000	161.37
2001	168.31
2002	175.43
2003	183.06
2004	190.65
2005	198.23
2006	206.54
2007	215.15
2008	225.25
2009	236.27
2010	247.61
2011	259.55
2012	270.99
2013	282.48
2014	294.03
2015	305.57
2016	317.44