Year	Number of
1990	103.28
1991	102.89
1992	101.87
1993	100.98
1994	100.73
1995	101.7
1996	104.15
1997	108.24
1998	113.57
1999	118.1
2000	122.54
2001	125.28
2002	128.36
2003	131.81
2004	135.65
2005	140.08
2006	144.06
2007	148.43
2008	153.77
2009	159.76
2010	166.42
2011	173.08
2012	180.08
2013	187.22
2014	194.87
2015	202.8
2016	209.57