Year	Number of Firms
1992-01-01	12
1997-01-01	13
2002-01-01	15
2003-01-01	22
2004-01-01	21
2005-01-01	21
2006-01-01	23
2007-01-01	21
2008-01-01	31
2009-01-01	22
2010-01-01	28
2011-01-01	18