Year	Number of Firms
1992-01-01	22
1997-01-01	28
2002-01-01	27
2003-01-01	28
2004-01-01	29
2005-01-01	40
2006-01-01	33
2007-01-01	51
2008-01-01	57
2009-01-01	53
2010-01-01	61
2011-01-01	30