Year	Number of
1990	119.47
1991	121
1992	123.52
1993	125.67
1994	129.31
1995	132.89
1996	137.13
1997	138.03
1998	140.91
1999	143.08
2000	146.06
2001	149.25
2002	149.78
2003	151.39
2004	154.97
2005	156.75
2006	158.32
2007	160.13
2008	163.36
2009	166.91
2010	170.61
2011	174.1
2012	178.02
2013	182.42
2014	186.63
2015	191.37
2016	196.33