Year	Number of
1990	91.56
1991	92.78
1992	94.87
1993	94.67
1994	96.99
1995	99.86
1996	100.37
1997	101.52
1998	104.58
1999	108.71
2000	110.47
2001	111.05
2002	109.61
2003	106.28
2004	103.85
2005	104.2
2006	109
2007	113.52
2008	117.55
2009	119.86
2010	122.9
2011	122.71
2012	124.5
2013	125.53
2014	128.83
2015	130.85
2016	134.18