How is the zakat calculated for a house that was sold for the same price it was bought for, after ten years of intending to trade with it, given the impossibility of selling it during that period due to poor financial conditions?

If the house was bought for the purpose of trade, its zakat for the past ten years must be paid. Zakat is calculated by knowing the value of the house at the end of each hawl (lunar year), and zakat is paid for each year based on that value. The hawl to be considered is the hawl of the money with which the house was bought. Caution must be exercised in paying zakat to clear one's liability.