condition mean min max 4 h after light 1975.9 1975.9 1975.9 8 h after light 2229.6 2043.3 2415.9 12 h after light 2751.75 2696.7 2806.8 4 h after dark 2255.8 1990.8 2520.8 8 h after dark 1921.95 1246.6 2597.3 12 h after dark 1153.0 944.8 1361.2