Year	Number of
1990	493.08
1991	480.7
1992	465.63
1993	450.98
1994	434.74
1995	420.37
1996	414.37
1997	400.37
1998	389.93
1999	376.51
2000	365.13
2001	354.88
2002	352.45
2003	351.5
2004	345.8
2005	344.28
2006	344.68
2007	338.52
2008	334.7
2009	335.84
2010	333.48
2011	328.79
2012	324.1
2013	320.43
2014	319.67
2015	318.17
2016	319.75