Year	Number of Firms
1997-01-01	4
2002-01-01	2
2003-01-01	1
2004-01-01	2
2005-01-01	1
2008-01-01	1
2009-01-01	2
2010-01-01	1
2011-01-01	2
2013-01-01	2
2014-01-01	1
2016-01-01	3