Year	Number of Firms
1992-01-01	3
1997-01-01	2
2002-01-01	1
2003-01-01	3
2004-01-01	1
2006-01-01	1
2007-01-01	1
2009-01-01	1
2010-01-01	3
2011-01-01	1
2013-01-01	1
2016-01-01	3