Year	Number of
1990	398.75
1991	392.13
1992	389.08
1993	389.48
1994	378.7
1995	375.55
1996	366.92
1997	355.49
1998	351.77
1999	347.42
2000	336.92
2001	337.45
2002	334.98
2003	330.81
2004	324.06
2005	318.22
2006	315.47
2007	317.68
2008	318.68
2009	317.6
2010	314.11
2011	318.55
2012	317.44
2013	313.71
2014	305.71
2015	307.23
2016	307.34