Year Number of 1990 26323.55 1991 27139.86 1992 28050.89 1993 28765.46 1994 29675.58 1995 30590.14 1996 31691.01 1997 32862.04 1998 33829.87 1999 34805.51 2000 35869.05 2001 36700.96 2002 37525.14 2003 38434.44 2004 39610.87 2005 40958.67 2006 42204.15 2007 43703.74 2008 45256.13 2009 46991.14 2010 48909.71 2011 50629.27 2012 52163.73 2013 54367.21 2014 56856.31 2015 59139.66 2016 60462.36