Year	Number of
1990	98.45
1991	99.56
1992	101.31
1993	102.71
1994	106.16
1995	106.09
1996	104.52
1997	103.64
1998	102.09
1999	103.52
2000	98.89
2001	98
2002	96.45
2003	96.01
2004	94.76
2005	98.27
2006	97.63
2007	98.29
2008	100.76
2009	103.47
2010	107.81
2011	108.34
2012	111.3
2013	111.73
2014	113.41
2015	112.24
2016	112.37