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