Year	Number of
1990	283.41
1991	294.41
1992	308.09
1993	318.73
1994	328.43
1995	335.56
1996	339.48
1997	338.79
1998	335.41
1999	329.06
2000	317.06
2001	312.32
2002	298.68
2003	294.43
2004	291.08
2005	289.42
2006	283.27
2007	279.96
2008	286.48
2009	291.35
2010	299.87
2011	302.56
2012	313.03
2013	321.1
2014	326.71
2015	331.2
2016	335.3