Year	Number of
1990	119.76
1991	119.04
1992	118.65
1993	118.19
1994	119.02
1995	120.6
1996	123.19
1997	127.12
1998	132.09
1999	135.06
2000	137.44
2001	138.15
2002	138.9
2003	139.76
2004	140.44
2005	141.22
2006	141.6
2007	141.94
2008	142.44
2009	143.32
2010	144.63
2011	145.32
2012	146.31
2013	147.8
2014	149.65
2015	151.66
2016	154.21