| Range | O | % | E | % | χ2 | df | p |
| ±13 days ±21 days ±34 days ±55 days ±89 days | 5 5 9 15 24 | 12.20 12.20 21.95 36.59 58.54 | 3.80 6.10 9.77 15.39 23.75 | 9.28 14.88 23.83 37.54 57.92 | 0.42 0.23 0.08 0.02 0.01 | 1 1 1 1 1 | 0.5181 0.6293 0.7777 0.8999 0.9370 |