Year	Number of
1990	331.99
1991	327.28
1992	319.37
1993	313.74
1994	302.7
1995	295.46
1996	286.64
1997	276.87
1998	268.9
1999	262.54
2000	249.66
2001	251.02
2002	245.67
2003	243.05
2004	240.5
2005	239.74
2006	236.41
2007	230.5
2008	225.64
2009	221.92
2010	218.32
2011	214.16
2012	211.52
2013	208.28
2014	206.46
2015	204.9
2016	204.61