| Standard pathways: occurrence probabilities | ||||
| Spatial distribution | Technological linkage | Agent involved | p | |
| Type IV | Type IV | Type IV | 0.28 | 0.83 |
| Type II | Type II | Type II | 0.19 | |
| Type I | Type I | Type I | 0.19 | |
| Type III | Type III | Type III | 0.17 | |
| Not-standard pathways: occurrence probabilities | ||||
| Type I | Type I | Type III | 0.11 | 0.17 |
| Type I | Type I | Type IV | 0.03 | |
| Type I | Type IV | Type IV | 0.03 | |