Year	Number of Firms
1992-01-01	22
1997-01-01	26
2002-01-01	20
2003-01-01	20
2004-01-01	20
2005-01-01	30
2006-01-01	19
2007-01-01	25
2008-01-01	35
2009-01-01	30
2010-01-01	31
2011-01-01	19