Year Number of 1990 240.23 1991 249.18 1992 260.3 1993 272.51 1994 285.93 1995 300.11 1996 322.88 1997 346.91 1998 376.08 1999 409.93 2000 450.77 2001 493.65 2002 547.32 2003 615.06 2004 690.3 2005 772.2 2006 835.41 2007 898.06 2008 967.62 2009 1051.2 2010 1156.46 2011 1240.59 2012 1343.81 2013 1462.01 2014 1578.31 2015 1684.73 2016 1810.17