Year Number 1996 313391.54 1997 311116.82 1998 302600.31 1999 296940.93 2000 306472.5 2001 306733.89 2002 320944.51 2003 330542.54 2004 354737.37 2005 385577.39 2006 389728.34 2007 392348.65 2008 395157.82 2009 399757.26 2010 409511.63 2011 423222.43 2012 425131.48 2013 426596.66 2014 428140.59 2015 428203.78 2016 428476.45 2017 430198.17 2018 435033.88 2019 438020.45 2020 455855.57