| Firms listed in First Section of TSE from FY 2004-2011 | 22,824 |
| - missing audit fee information | (5929) |
| - missing regression control variables | (332) |
| - firms will multiple auditors (joint audit) | (184) |
| - industry with less than ten listed companies within an industry-year | (164) |
| - firms from banking, insurance, securities & other financial industries | (905) |
| Final sample (firm years) | 15,310 |