| Region | Male | Female | Total |
| Cervical | 5 | 4 | 9 (18.7%) |
| Thoracic | 10 | 18 | 28 (54.8%) |
| Lumbar | 3 | 2 | 5 (10.4%) |
| Cervicothoracic | 2 | 1 | 3 (6.2%) |
| Thoracolumbar | 0 | 1 | 1 (2.1%) |
| Lumbosacral | 1 | 1 | 2 (4.2%) |
| Total | 21 | 27 | 48 (100.0%) |