Year Number of 1990 968.14 1991 1003.39 1992 1014.71 1993 1026 1994 1046.55 1995 1043.9 1996 1049.9 1997 1031.4 1998 1005.38 1999 972.13 2000 930.51 2001 893.91 2002 844.53 2003 806.73 2004 765.29 2005 730.02 2006 707.4 2007 685.4 2008 654.82 2009 634.77 2010 624.29 2011 605.88 2012 599.35 2013 593.43 2014 595.58 2015 598.89 2016 643.48