Year	Number of Firms
1992-01-01	10
1997-01-01	10
2002-01-01	21
2003-01-01	21
2004-01-01	20
2005-01-01	31
2006-01-01	30
2007-01-01	37
2008-01-01	33
2009-01-01	25
2010-01-01	37
2011-01-01	17