Year Number of 1990 3111.32 1991 3219.62 1992 3328.95 1993 3442.48 1994 3569.58 1995 3710.57 1996 3781.16 1997 3857.43 1998 3942.44 1999 4027.01 2000 4115.2 2001 4216.44 2002 4311.54 2003 4413.9 2004 4529.96 2005 4652.19 2006 4706.33 2007 4761.3 2008 4822.61 2009 4894.33 2010 4971.13 2011 5026.94 2012 5084.98 2013 5110.6 2014 5145.34 2015 5190.35 2016 5236.36