Year	Number of Firms
1992-01-01	3
1997-01-01	3
2002-01-01	6
2003-01-01	6
2004-01-01	5
2005-01-01	5
2006-01-01	6
2007-01-01	7
2008-01-01	12
2009-01-01	12
2010-01-01	7
2011-01-01	3