Year	Number of
1990	354.28
1991	346.15
1992	334.57
1993	324.98
1994	310.6
1995	302.92
1996	293.37
1997	283.7
1998	276
1999	270.65
2000	260.58
2001	264.2
2002	259.63
2003	258.43
2004	256.1
2005	256.37
2006	253.41
2007	247.21
2008	243.65
2009	239.79
2010	237.39
2011	236.31
2012	234.93
2013	231.24
2014	228.66
2015	224.59
2016	222.44