condition mean min max 4 h after light 8.6704905 8.045454 9.295527 8 h after light 7.745823 7.462681 8.028965 12 h after light 7.840368 7.534815 8.145921 4 h after dark 8.604502 8.570812 8.638192 8 h after dark 8.35003 8.090913 8.609147 12 h after dark 8.185253 8.185253 8.185253