Year Number of Firms 1992-01-01 305 1997-01-01 488 2002-01-01 486 2003-01-01 527 2004-01-01 522 2005-01-01 521 2006-01-01 473 2007-01-01 489 2008-01-01 500 2009-01-01 483 2010-01-01 504 2011-01-01 544 2012-01-01 545 2013-01-01 534 2014-01-01 546 2015-01-01 515 2016-01-01 523