condition	mean	min	max
4 h after light	2.1	2.1	2.1
8 h after light	1.4	1.0	1.8
12 h after light	18.7	15.7	21.7
4 h after dark	1.4	1.0	1.8
8 h after dark	2.9	0.8	5.0
12 h after dark	1.25	1.1	1.4