Year	Number of
1990	202.01
1991	201.95
1992	201.75
1993	208.47
1994	209.22
1995	203.35
1996	184.46
1997	176.86
1998	180.86
1999	176.43
2000	171.08
2001	183.12
2002	187.28
2003	199.55
2004	207.93
2005	223.16
2006	241.69
2007	250.37
2008	248
2009	249.82
2010	251.12
2011	255.16
2012	254.98
2013	261.45
2014	254.49
2015	254.44
2016	257.15