Year	Number of Firms
1997-01-01	5
2002-01-01	5
2003-01-01	8
2004-01-01	11
2005-01-01	6
2006-01-01	9
2007-01-01	9
2008-01-01	5
2009-01-01	8
2010-01-01	13
2011-01-01	9