condition mean min max 4 h after light 0.5 0.5 0.5 8 h after light 0.95 0.9 1.0 12 h after light 1.1 0.7 1.5 4 h after dark 1.6 1.2 2.0 8 h after dark 9.799999999999999 0.9 18.7 12 h after dark 4.6 1.2 8.0