Year Number of Firms 1992-01-01 397 1997-01-01 571 2002-01-01 503 2003-01-01 538 2004-01-01 520 2005-01-01 503 2006-01-01 499 2007-01-01 554 2008-01-01 576 2009-01-01 565 2010-01-01 575 2011-01-01 577 2012-01-01 537 2013-01-01 553 2014-01-01 577 2015-01-01 571 2016-01-01 578