Year	Number of
1990	119.16
1991	120.13
1992	125.8
1993	125.3
1994	122.12
1995	126.28
1996	130.5
1997	131.33
1998	134.95
1999	135.38
2000	134.19
2001	136.79
2002	137.05
2003	143.18
2004	147.54
2005	155.59
2006	162.69
2007	161.13
2008	167.29
2009	167.08
2010	164.48
2011	163.38
2012	167.52
2013	170.47
2014	171.58
2015	178.29
2016	182.17