| Model | K | AIC | ΔAIC | AICwt |
| p(month + effort) | 6 | 3300.56 | 0.00 | 0.86 |
| p(month + effort + year) | 9 | 3304.10 | 3.55 | 0.14 |
| p(effort) | 5 | 3409.91 | 109.35 | 0.00 |
| p(effort + year) | 8 | 3413.84 | 113.29 | 0.00 |
| p(month + year) | 8 | 3501.73 | 201.17 | 0.00 |
| p(month) | 5 | 3503.15 | 202.59 | 0.00 |
| p(year) | 7 | 3614.31 | 313.75 | 0.00 |
| p(.) | 4 | 3621.90 | 321.34 | 0.00 |