The amount of the nisab for silver and the ruling on one who delays its zakah for ten years

Question:
I have silver made for wearing, but it has not been worn because it is tight, and it has been with me for more than ten years. What should be done regarding its zakah if it is sold? Is it zakaed for one year only?

Answer:
He should pay its zakah, whether it is sold or not, if it has reached the nisab. He should pay it for the past years, if it reaches the nisab of one hundred and forty mithqals of silver. The nisab of silver is one hundred and forty mithqals, which amounts to fifty-six Saudi Riyals of the well-known Saudi silver. If this piece reaches the nisab, he pays its zakah for the past years, a quarter of a tenth for each year, which is two and a half percent.

Question: For ten years?

Answer: For ten years. He is the one who was negligent, and he must repent to Allah and turn to Him regarding his negligence and his delay in paying it.