Cargo booking amount (billing) the incoming order amount for (with thing of the ratio of booking, making receipt index of semiconductor industry it is widely used.

Dividing 3 monthly average incoming order amounts of all industries, with shipment amount between same period, it calculates BB ratio. For example, when BB ratio 0.8 is, shipment new incoming order 80 comes to the point of being vis-a-vis 100, as for "business" of industry it is found that it is in the downward phase of the business cycle.