condition mean min max 4 h after light 1.5 1.5 1.5 8 h after light 2.05 1.4 2.7 12 h after light 2.9 2.3 3.5 4 h after dark 1.85 1.8 1.9 8 h after dark 6.75 5.7 7.8 12 h after dark 3.6500000000000004 1.6 5.7