Year Number of 1990 3589.68 1991 3766.67 1992 3955.19 1993 4151.5 1994 4350.9 1995 4563.05 1996 4725.27 1997 4900.67 1998 5084.93 1999 5270.75 2000 5463.87 2001 5614.38 2002 5776.29 2003 5945.64 2004 6124.28 2005 6317.92 2006 6575.35 2007 6857.89 2008 7159.29 2009 7483.55 2010 7831.4 2011 8072.96 2012 8332.31 2013 8597.68 2014 8844.63 2015 9112.87 2016 9392.38