What is the relevant valuation date for a PET?

[Umar]

Hi

If someone passes away, but gave away a property 5 years ago, for calculating the use of the NRB, does one value the property at date of death or date of gift?

e.g. Value at date of gift was £100k
Value at date of death was £150k.

Does one use £100k or £150k when working out how much NRB has been used up by the PET?

[maths]

Date of gift.