Year Number of 1990 6810.49 1991 7116.07 1992 7259.12 1993 7407.86 1994 7470.05 1995 7602.39 1996 7305.96 1997 6986.33 1998 6596.86 1999 6718.34 2000 6713.73 2001 6576.61 2002 6530.66 2003 6522.59 2004 6517.82 2005 6542.2 2006 6280.49 2007 6433.7 2008 6468.71 2009 6057.96 2010 5889.14 2011 5738.07 2012 5883.49 2013 5870.66 2014 5622.75 2015 5673.14 2016 5790.67