Year	Number of
1990	92.04
1991	92.21
1992	91.39
1993	89.37
1994	88.56
1995	86.18
1996	83.01
1997	82.03
1998	80.26
1999	80.69
2000	81.54
2001	83.62
2002	85.83
2003	89.11
2004	92.41
2005	95.64
2006	98.25
2007	100.44
2008	102.75
2009	105.55
2010	109.39
2011	114.05
2012	114.82
2013	115.77
2014	119.35
2015	123.33
2016	126.7