| Distribution | Frequency (person) | (%) | |
| Profession | Construction engineer | 14 | 31 |
| Construction manager | 10 | 23 | |
| Safety engineer | 10 | 23 | |
| Tower crane operator | 10 | 23 | |
| Careers | 10 years - 20 years | 25 | 57 |
| More than 20 years | 19 | 43 | |