Table 3. Daily enamel extension rates in buccal and lingual enamel of Soay sheep mandibular first molars.

Period (postnatal age in days)	Enamel extension rate (µm/day), buccal side			Enamel extension rate (µm/day), lingual side
	mean	range	N	Mean	range	N
0–14 (6–20)*	177.6	147.7–219.0	6	217.3	148.2–274.5	6
14–28 (20–34)*	168.4	148.1–199.1	6	189.8	160.4–260.1	6
28–42 (34–48)*	180.0	136.8–225.5	6	181.2	129.8–217.5	6
42–56 (48–62)*	131.7	106.6–166.4	6	126.0	106.5–176.9	6
56–90	109.9		1	111.2		1
147–161	40.4	36.9–43.9	2
161–175	35.5	32.0–39.0	2
175–196	35.0	34.6–35.4	2
188–210	33.2	29.5–35.4	2	30.5		1
202–223	27.1	26.0–28.3	2	25.0		1
216–244	28.0	26.1–29.9	2
237–258	29.3	27.9–30.8	2	19.5		1

N = number of individuals from which data were recorded in the given postnatal age period. The overlap in the last five periods result from the different birth dates of the respective individuals.

^*Data in parenthesis refer to specimen #79768 in which injection started at day 6 after birth.