Year	Number of
1990	110.01
1991	110.93
1992	112.14
1993	111.76
1994	110.95
1995	109.42
1996	107.65
1997	105
1998	100.27
1999	96.08
2000	100.08
2001	99.88
2002	99.58
2003	99.09
2004	98.89
2005	98.05
2006	97.09
2007	98.59
2008	100.09
2009	100.66
2010	101.96
2011	101.38
2012	103.65
2013	105.56
2014	107.42
2015	109.46
2016	111.63