Zakat Question: Paying zakat on money that was held for 14 years

I invested in bonds in 2006 when I was a child. I did not know this was haram as we did not have the knowledge. I have since withdrawn the £1000 investment.
My question is, do I pay zakat on just the 1000. So I would end up paying £25?
Or do I pay zakat on the amount over the years.
E.g. Zakat due for 2006 would be 2.5% of 1000
2007 would be 2.5% of 975
and so on…


May Allah bless you.

You would pay zakat over the years as you mentioned, starting from the time reached puberty, and every year thereafter.

And Allah knows best!