Year	Number of
1990	226.43
1991	228.31
1992	230.78
1993	233.81
1994	236.8
1995	239.79
1996	242.33
1997	245.26
1998	246.78
1999	252.73
2000	256.66
2001	263.06
2002	261.86
2003	261.74
2004	262.15
2005	265.15
2006	265.12
2007	264.77
2008	266.72
2009	266.32
2010	266.3
2011	263.59
2012	264.47
2013	265.62
2014	267.1
2015	268.74
2016	270.98