Year	Number of
1990	236.09
1991	231.75
1992	228.33
1993	236.85
1994	260.32
1995	273.77
1996	290.82
1997	298.12
1998	292.64
1999	299.43
2000	296.54
2001	284.26
2002	276.51
2003	284.63
2004	291.53
2005	301.04
2006	305.3
2007	312.97
2008	320.53
2009	320.62
2010	325.17
2011	325
2012	325.34
2013	328.85
2014	332.06
2015	337.13
2016	342.18