Depreciation charged (IAS16 PPE)

Aphrodite Co has a year end of 31 December and operates a factory which makes computer chips for mobile phones.

It purchased a machine on 1 July 20X3 for $80,000 which had a useful life of ten years and is depreciated on the
straight-line basis, time apportioned in the years of acquisition and disposal.

The machine was revalued to $81,000 on 1 July 20X4.

There was no change to its useful life at that date.

A fire at the factory on 1 October 20X6 damaged the machine leaving it with a lower operating capacity.

The accountant considers that Aphrodite Co will need to recognise an impairment loss in relation to this damage.

The accountant has ascertained the following information at 1 October 20X6:
(1)
The carrying amount of the machine is $60,750.
(2)
An equivalent new machine would cost $90,000.
(3)
The machine could be sold in its current condition for a gross amount of $45,000. Dismantling costs would amount
to $2,000.
(4)
In its current condition, the machine could operate for three more years which gives it a value in use figure of
$38,685.
In accordance with IAS 16 Property, Plant and Equipment, what is the depreciation charged to Aphrodite Co’s
profit or loss in respect of the machine for the year ended 31 December 20X4?

A $9,000
B $8,000
C $8,263
D $8,500

The answer shows like below, but why the depreciation is 6months (1Jan to 30June X4)? Is it should be 1 year depreciation from 1.July.X3 to they revalue the amount(1.July20x4)? So my answer should be 8000(80000/10)+4500(81000/9×6/12)

Depreciation 1 January to 30 June 20X4 (80,000/10 × 6/ 12) = 4,000
Depreciation 1 July to 31 December 20X4 (81,000/9 × 6/ 12) = 4,500
Total depreciation = 8,500