Year	Number of
1990	211.84
1991	227.22
1992	236.65
1993	247.61
1994	261.46
1995	266.54
1996	270.85
1997	266.76
1998	267.44
1999	267.5
2000	265.94
2001	262.74
2002	262.42
2003	262.84
2004	262.45
2005	265.06
2006	266.17
2007	266.12
2008	263.39
2009	264.7
2010	260.29
2011	255.65
2012	247.76
2013	246.88
2014	251.39
2015	258.22
2016	264.2