| Year | Greek Audit Firms | USA Audit Firms | |
| Audit Fees % | Other Services Fees % | Other Services Fees % | |
| 2018 | 61.39% | 38.61% | 10.30% |
| 2019 | 61.89% | 38.11% | 9.90% |
| 2020 | 62.69% | 37.31% | 9.20% |
| 2021 | 64.05% | 35.95% | 8.90% |