Year	Number of
1990	111.65
1991	114.78
1992	118.29
1993	122.28
1994	126.48
1995	130.96
1996	135.32
1997	140.01
1998	143.46
1999	146.63
2000	148.54
2001	151.95
2002	151.46
2003	152.46
2004	154.01
2005	157.5
2006	159.24
2007	161.27
2008	164
2009	166.9
2010	169.3
2011	170.21
2012	173.28
2013	176.3
2014	179.63
2015	183.08
2016	186.98