condition mean min max 4 h after light 1.3 1.3 1.3 8 h after light 2.35 1.7 3.0 12 h after light 1.6 0.8 2.4 4 h after dark 3.15 1.2 5.1 8 h after dark 1.1 0.7 1.5 12 h after dark 0.75 0.7 0.8