Year	Number of
1990	578.6
1991	558.43
1992	535.83
1993	519.54
1994	493.42
1995	475.05
1996	466.32
1997	451.74
1998	435.49
1999	421.91
2000	411.63
2001	403.51
2002	392.4
2003	383.75
2004	374.57
2005	362.76
2006	355.52
2007	348.67
2008	344.42
2009	336.62
2010	332.82
2011	333.3
2012	334.2
2013	335.57
2014	330.59
2015	335.95
2016	334.64