Year	Number of
1990	229.55
1991	224.47
1992	211.23
1993	200.73
1994	191.51
1995	184.48
1996	187.55
1997	189.3
1998	194.27
1999	202.02
2000	210.25
2001	225.62
2002	241.02
2003	252.73
2004	265.77
2005	270.43
2006	265.21
2007	259.68
2008	253.75
2009	251.25
2010	247.43
2011	239.73
2012	235.35
2013	232.52
2014	234.37
2015	234.56
2016	235.64