The world average was 5.7 pounds for every pound of shrimp. The Avoirdupois units of mass and weight differ for units larger than a pound (lb). There are 12 troy ounces in the now obsolete troy pound. Coloured rag was worth about two pence per pound. Rotherham had a mill valued at an ordinary half of one pound sterling. Trainees must be able to swim with 50 pound weights. It was initially equivalent to one pound sterling. Over time the ingredients for pound cake changed. A rocket carrying about one pound of powder could travel almost . But it was difficult to do arithmetic with things like pound or foot. One pound of marijuana yields from 1/5 to 1/10 of a pound of hash oil. However, they differ when dealing with units larger than the pound. This was a form of official metric pound. The "International Avoirdupois Pound" was then created. Cooks also made yeast, sponge and pound cakes.