condition mean min max 4 h after light 4.9 4.9 4.9 8 h after light 10.1 2.2 18.0 12 h after light 2.45 1.9 3.0 4 h after dark 2.75 2.4 3.1 8 h after dark 6.15 4.8 7.5 12 h after dark 4.75 3.9 5.6