Year Number 1995 14193466.931805676 1996 16049754.025331588 1997 16643490.66039536 1998 17777716.281703483 1999 19153012.32653074 2000 19437981.380174156 2001 20377864.549196888 2002 22023890.382242594 2003 22796021.35522792 2004 24570128.188448586 2005 26229482.297248088 2006 29607860.52354995 2007 34490086.89441564 2008 35560286.30261624 2009 36521793.40136198 2010 40138969.92843513 2011 40525618.32022657 2012 42980384.60133041 2013 44484730.55130008 2014 46265055.584042154 2015 48672074.10386219 2016 50877194.3830237 2017 52496629.85747189 2018 56247033.37360386 2019 55555231.29541253