condition mean min max 4 h after light 6.2 6.2 6.2 8 h after light 4.8 1.9 7.7 12 h after light 4.6 1.7 7.5 4 h after dark 2.8 1.9 3.7 8 h after dark 3.55 1.8 5.3 12 h after dark 6.35 5.6 7.1