Year	Number of Firms
1992-01-01	2
1997-01-01	5
2002-01-01	7
2003-01-01	2
2004-01-01	2
2005-01-01	3
2006-01-01	5
2007-01-01	3
2008-01-01	2
2009-01-01	3
2010-01-01	1
2011-01-01	1