Year Number of Firms 1997-01-01 4 2003-01-01 2 2004-01-01 4 2005-01-01 4 2006-01-01 6 2007-01-01 11 2008-01-01 7 2009-01-01 2 2010-01-01 7 2011-01-01 7 2012-01-01 8 2013-01-01 8 2014-01-01 8 2015-01-01 7 2016-01-01 4