Year Number of 1990 611.98 1991 635.57 1992 661.18 1993 688.96 1994 719.37 1995 754.54 1996 784.2 1997 832.73 1998 849.13 1999 885.7 2000 944.98 2001 955.21 2002 1020.07 2003 1064.88 2004 1109.53 2005 1144.76 2006 1185.53 2007 1225.59 2008 1302.25 2009 1312.48 2010 1368.96 2011 1377.52 2012 1399.03 2013 1422.86 2014 1455.66 2015 1494.29 2016 1539.24