If one has trade goods, such as a shop, does he assess what is in it without needing to look at his original capital?

Question : He says: And he asked about the like of the zakah on trade goods: Is it the case that if one has a shop, for example, he assesses what is in it and does not need to look at the original capital?

Answer : And it is so. As for trade goods, once the lunar year has passed, you assess what you have of that which is subject to zakah, whether it has increased beyond the original capital or decreased.