Cephalic Index

Gray et.al. Obstet Gynecol 1987:74:600-603

GA (wks)	1SD	Mean	1SD
14	77.8	81.5	85.3
15	77.3	81	84.8
16	76.8	80.5	84.3
17	76.4	80.1	83.9
18	76	79.7	83.5
19	75.7	79.4	83.2
20	75.4	79.1	82.9
21	75.1	78.8	82.6
22	74.9	78.6	82.4
23	74.7	78.4	82.2
24	74.6	78.3	82
25	74.4	78.1	81.9
26	74.3	78	81.8
27	74.3	78	81.8
28	74.3	78	81.8
29	74.3	78	81.8
30	74.4	78.1	81.9
31	74.5	78.2	82
32	74.6	78.3	82.1
33	74.8	78.5	82.3
34	75	78.7	82.5
35	75.2	78.9	82.7
36	75.5	79.2	83
37	75.8	79.5	83.3
38	76.2	79.9	83.7
39	76.6	80.3	84.1
40	77	80.7	84.5