Year	Number of
1990	102.05
1991	104.17
1992	108.64
1993	112.79
1994	119.32
1995	121.83
1996	123.88
1997	127.82
1998	130.71
1999	136.9
2000	142.02
2001	147.87
2002	153.14
2003	158.68
2004	165.81
2005	172.42
2006	178.37
2007	183.22
2008	188.28
2009	192.96
2010	198.05
2011	203.77
2012	210.26
2013	217.75
2014	225.25
2015	233.79
2016	243.17