Year	Number of
1990	105.08
1991	104.1
1992	102.98
1993	101.97
1994	101.47
1995	101.8
1996	103.13
1997	105.51
1998	108.62
1999	112
2000	115.56
2001	118.12
2002	120.96
2003	123.93
2004	126.99
2005	130.32
2006	132.93
2007	135.33
2008	137.92
2009	140.71
2010	143.93
2011	146.25
2012	149.11
2013	152.25
2014	155.67
2015	159.34
2016	163.58