Year Number of 1990 370.94 1991 384.26 1992 398.02 1993 410.24 1994 427.25 1995 450 1996 483.96 1997 522.19 1998 562.98 1999 603.62 2000 643.89 2001 681.57 2002 720.98 2003 770.33 2004 824.24 2005 883.99 2006 917.89 2007 954.61 2008 997.03 2009 1040.73 2010 1085.06 2011 1097.35 2012 1108.67 2013 1119.71 2014 1131.7 2015 1145.51 2016 1160.22