Year Number of 1990 19113.33 1991 20156.85 1992 21061.69 1993 21195 1994 21544.94 1995 22482.74 1996 21111.86 1997 19441.49 1998 17721.25 1999 17700.55 2000 17697.35 2001 16940.97 2002 16378.15 2003 15989.66 2004 15917.49 2005 15901.47 2006 14847.89 2007 14968.11 2008 14668.17 2009 12830.14 2010 12112.1 2011 11757.63 2012 12050.04 2013 11990.56 2014 11552.18 2015 11692.95 2016 11885.73