Year Number of 1990 4214.91 1991 4308.58 1992 4309.46 1993 4318.83 1994 4287.06 1995 4327.99 1996 4003.59 1997 3720.8 1998 3451.68 1999 3369.36 2000 3255.23 2001 3122.29 2002 3032.95 2003 2955.38 2004 2899.27 2005 2831.89 2006 2701.66 2007 2705.15 2008 2688.28 2009 2531.8 2010 2445.89 2011 2403.49 2012 2468.02 2013 2478.86 2014 2403.58 2015 2452.49 2016 2515.9