Year Number of 1990 36599.22 1991 37142.01 1992 37753.9 1993 38397.95 1994 39079.55 1995 39806.38 1996 40240.38 1997 40740.02 1998 41270.76 1999 41789.2 2000 42373.61 2001 42370.66 2002 42350.34 2003 42327.65 2004 42367.57 2005 42515.65 2006 42259.59 2007 42037.48 2008 41831.19 2009 41675.43 2010 41592.55 2011 42184.57 2012 42772.97 2013 43357.32 2014 43956.37 2015 44579.66 2016 45229.22