Year Number of 1990 1492.49 1991 1476.06 1992 1455.1 1993 1445.99 1994 1419.78 1995 1432.43 1996 1427.47 1997 1408.2 1998 1403.42 1999 1404.41 2000 1388.17 2001 1376.88 2002 1360.83 2003 1357.55 2004 1335.46 2005 1335.55 2006 1309.37 2007 1300.62 2008 1288.79 2009 1281.38 2010 1267.16 2011 1259.8 2012 1258.49 2013 1241.71 2014 1232.29 2015 1236.04 2016 1240.7