Year Number of 1990 495.6 1991 526.79 1992 551.94 1993 577.6 1994 628.79 1995 662.52 1996 688.36 1997 742.35 1998 806.1 1999 882.54 2000 978.39 2001 1033.56 2002 1098.89 2003 1155.04 2004 1211.42 2005 1248 2006 1294.42 2007 1334 2008 1371.76 2009 1424.74 2010 1477.68 2011 1503.99 2012 1538.16 2013 1549.12 2014 1572.06 2015 1599.42 2016 1629.27