Table 3. Survival distribution in female 129/Sv mice exposed to various light regimens.

	Number of survivors at the age of: (days)
Group	300	400	500a	550	600	650	700	750	800	850	900	950	1000
LD	46	46	43	42	38	34	32	27	22	14	10	2	0
LL	46	43	41	38	38	34	28b	20b	13b	3b	1a	0	0

^a The first tumor detected in this interval. ^bThe difference with the controls of corresponding age is significant, p < 0.05; Fischer’s exact test.