condition mean min max 4 h after light 3.6 3.6 3.6 8 h after light 2.2 2.1 2.3 12 h after light 4.15 3.0 5.3 4 h after dark 2.8 2.5 3.1 8 h after dark 3.95 3.1 4.8 12 h after dark 5.550000000000001 4.7 6.4