Year Number 1996 3385.12 1997 3768.19 1998 3724.97 1999 4017.86 2000 4231.85 2001 4356.17 2002 4681.53 2003 4478.15 2004 4602.28 2005 4861.52 2006 5552.9 2007 5659.69 2008 6217.93 2009 6802.37 2010 7135.9 2011 7624.35 2012 7753.63 2013 7895.61 2014 8218.57 2015 8305.92 2016 8485.48 2017 8624.13 2018 9090.82 2019 8984.76 2020 9729.75