Year	Number of
1990	262.16
1991	268.91
1992	276.47
1993	285.12
1994	296.19
1995	307.63
1996	317.94
1997	325.27
1998	334.84
1999	343.89
2000	352.33
2001	353.41
2002	354.47
2003	354.09
2004	354.21
2005	351.1
2006	348.76
2007	346.77
2008	343.12
2009	345.18
2010	348.36
2011	348.88
2012	348.61
2013	347.86
2014	346.71
2015	347.54
2016	347.44