	Office and residential property			Ships			Ship equipment			Total
Cost:	US$’000			US$’000			US$’000			US$’000
Balance at 1 January 2020		2,733			85,534			271			88,538
Additions		539			20,833			83			21,455
Derecognition of right-of-use asset		(80	)		(18,449	)		(167	)		(18,696	)
Acquisitions of subsidiary (Note 39.1)		-			-			87			87
Adjustment (1)		(80	)		-			-			(80	)
Reclassification to disposal group held for sale (Note 38)		(399	)		-			-			(399	)
Effect of foreign currency exchange differences		34			-			-			34
Balance at 31 December 2020		2,747			87,918			274			90,939
Additions		371			20,254			243			20,868
Derecognition of right-of use-asset		(310	)		(12,285	)		(41	)		(12,636	)
Effect of foreign currency exchange differences		88			-			-			88
Balance at 31 December 2021		2,896			95,887			476			99,259

Accumulated depreciation:
Balance at 1 January 2020		601			30,307			142			31,050
Depreciation from continuing operations		946			24,507			167			25,620
Depreciation from discontinued operation		73			1,739			-			1,812
Derecognition of right-of-use asset		(80	)		(18,449	)		(167	)		(18,696	)
Adjustment (1)		(80	)		-			-			(80	)
Reclassification to disposal group held for sale (Note 38)		(82	)		-			-			(82	)
Effect of foreign currency exchange differences		3			-			-			3
Balance at 31 December 2020		1,381			38,104			142			39,627
Depreciation from continuing operations		938			34,781			117			35,836
Depreciation from discontinued operation		34			-			-			34
Derecognition of right-of-use asset		(310	)		(9,252	)		(41	)		(9,603	)
Effect of foreign currency exchange differences		54			-			-			54
Balance at 31 December 2021		2,097			63,633			218			65,948

Impairment:
Balance at 1 January 2020, 31 December 2020		-			2,250			-			2,250
Derecognition of right-of-use asset		-			(360	)		-			(360	)
Reversal of impairment from continuing operations		-			(1,046	)		-			(1,046	)
Balance at 31 December 2021		-			844			-			844

Carrying amount:
As at 31 December 2021		799			31,410			258			32,467
As at 31 December 2020		1,366			47,564			132			49,062

(1)

Refers to lease modification during the period.

Right-of-use assets are depreciated over the remaining period of the lease. The average lease term is between 1 and 4 years for property, between 1 and 5 years for ships, and between 2 and 4 years for ship equipment.

Depreciation expense of US$34,898,000 (2020: US$26,413,000 and 2019: US$30,449,000) for ships and ship equipment are recognised in cost of sales and the depreciation expense of US$938,000 (2020: US$1,019,000 and 2019: US$601,000) for office and residential property is recognised separately in administrative expense.

The Group has options to purchase certain ships at set prices at certain dates within the contracts. The exercise price is not included in the right-of-use assets for these ships because it is not reasonably certain that the options will be exercised.

For the year ended 31 December 2021, the Group recognised expense of US$90,763,000 (2020: US$42,946,000 and 2019: US$63,113,000) for short-term leases (i.e. a lease period of 12 months or less), US$58,000 (2020: US$84,000 and 2019: US$73,000) for leases of low value assets and US$90,763,000 (2020: US$42,946,000 and 2019: $55,952,000) for variable lease payments in connection with pool arrangements not included in the measurement of the lease liability.

Corresponding lease liabilities are disclosed in Note 24.