| 孕齡 |
長子男性 |
Not-firstborn男性 |
長子雌性 |
Not-firstborn雌性 |
| 23 |
26.3 |
26.6 |
25.8 |
26.1 |
| 24 |
27.4 |
27.7 |
26.9 |
27.2 |
| 25 |
28.6 |
28.9 |
28.1 |
28.3 |
| 26 |
29.8 |
30.1 |
29.3 |
29.5 |
| 27 |
31.1 |
31.4 |
30.5 |
30.8 |
| 28 |
32.4 |
32.7 |
31.8 |
32.1 |
| 29 |
33.7 |
34.1 |
33.1 |
33.4 |
| 30. |
35.1 |
35.5 |
34.5 |
34.8 |
| 31 |
36.5 |
36.9 |
35.9 |
36.2 |
| 32 |
38.0 |
38.4 |
37.3 |
37.7 |
| 33 |
39.5 |
39.8 |
38.7 |
39.1 |
| 34 |
40.9 |
41.3 |
40.1 |
40.5 |
| 35 |
42.3 |
42.7 |
41.5 |
41.9 |
| 36 |
43.6 |
44.0 |
42.8 |
43.2 |
| 37 |
44.8 |
45.2 |
44.0 |
44.4 |
| 38 |
45.8 |
46.3 |
45.0 |
45.4 |
| 39 |
46.7 |
47.1 |
45.8 |
46.3 |
| 40 |
47.3 |
47.8 |
46.4 |
46.9 |
| 41 |
47.8 |
48.2 |
46.9 |
47.4 |
| 42 |
48.0 |
48.4 |
47.1 |
47.5 |
