Year	Number of Firms
1997-01-01	1
2003-01-01	2
2004-01-01	1
2006-01-01	1
2007-01-01	1
2008-01-01	4
2009-01-01	1
2011-01-01	1
2012-01-01	1
2014-01-01	2
2015-01-01	1
2016-01-01	1