Year Number of 1990 23196.53 1991 23974.04 1992 24825.78 1993 25711.17 1994 26632.7 1995 27598.71 1996 27830.95 1997 28140.51 1998 28487.42 1999 28829.9 2000 29269.57 2001 29364.03 2002 29446.47 2003 29541.16 2004 29661.26 2005 29766.72 2006 30212.83 2007 30728.22 2008 31284.4 2009 31827.09 2010 32355.39 2011 33194.51 2012 34061.28 2013 34963.38 2014 35838.23 2015 36815.98 2016 37835.54