condition mean min max 4 h after light 3.4 3.4 3.4 8 h after light 6.95 4.5 9.4 12 h after light 22.85 6.1 39.6 4 h after dark 5.3 3.9 6.7 8 h after dark 29.2 27.4 31.0 12 h after dark 9.85 5.0 14.7