Year Number of Firms 1992-01-01 3 1997-01-01 2 2002-01-01 6 2003-01-01 7 2004-01-01 7 2005-01-01 5 2006-01-01 3 2007-01-01 4 2008-01-01 4 2009-01-01 6 2010-01-01 4 2011-01-01 4 2012-01-01 4 2013-01-01 3 2014-01-01 5 2015-01-01 5 2016-01-01 6