Year	Number of
1990	204.14
1991	208.92
1992	213.86
1993	219.77
1994	222.08
1995	223.95
1996	225.09
1997	226.31
1998	227.05
1999	226.94
2000	226
2001	228.16
2002	232.39
2003	230.85
2004	229.34
2005	230.27
2006	231.49
2007	233.33
2008	241.6
2009	246.48
2010	251.99
2011	255.35
2012	256.23
2013	258.22
2014	259.91
2015	269.14
2016	275.32