Year	Number of
1990	104.84
1991	105.11
1992	105.4
1993	104.2
1994	102.58
1995	100.17
1996	97.6
1997	94.46
1998	90.45
1999	87.67
2000	90.69
2001	90.18
2002	90.34
2003	90.54
2004	91.08
2005	91.07
2006	90.63
2007	92.01
2008	93.41
2009	94.15
2010	95.88
2011	95.85
2012	98.41
2013	100.67
2014	103
2015	105.52
2016	108.06