100   Transfer of land not used and occupied solely as a principal place of residence

If:

(a)  a transfer of land would be eligible for exemption under section 96, 97 or 98 but for the fact that the land is not land to which section 96 (1) (c), 97 (d) or 98 (d) applies because it was not used and occupied solely as a principal place of residence at the relevant time, and

(b)  the land value of the land was entitled to be reduced under section 9C or 9D of the Land Tax Management Act 1956 at the relevant time,

the amount on which the transfer is to be charged with ad valorem duty is to be reduced in the same proportion as the land value was entitled to be reduced under section 9C or 9D of the Land Tax Management Act 1956.