Hi let's said 20 years ago,
I bought a property and already got sijil tanah.
But 20 years ago I no longer know how much is my purchase price.

If let's said 4-5 years ago I bought a property,
i already forgot my purchase my property price.
Then I want to sell it my property.
Then how to proof that I will be charged for rpgt?
I mean how can I know my first time property price?
Let's said I still in loan or already got sijil tanah.
How can I know my 5 years ago property price?
How can I know my 20 years ago property price?
Do rpgt know during my purchase time of the property price?