Calculating zakaat on gold for previous years
Q: A person bought 250 grams of gold in Dec 2016 and was unable to pay zakaat during the last 4 years. Now he wants to make up for the missed zakaat.
The question is, should he calculate the due zakaat of all 4 years on the current gold rates? Or should he calculate 2017 zakaat on 2017 gold rate, 2018 zakat on 2018 gold rate and so on?