Year	Number of
1990	121.63
1991	121.65
1992	121.36
1993	120.99
1994	120.93
1995	121.52
1996	123
1997	125.03
1998	127.68
1999	129.14
2000	130
2001	132.24
2002	137.61
2003	142.05
2004	145.88
2005	149.98
2006	154.3
2007	158.78
2008	163.28
2009	166.57
2010	169.55
2011	174.1
2012	182.45
2013	187.46
2014	193.02
2015	198.99
2016	206.84