5.	Acquired Intangibles

The following table summarizes the life, the gross carrying value of our acquired intangible assets, and the related accumulated amortization as of the end of fiscal 2018 and 2017 (in millions):


	Weighted Average		2018							2017
	Life in Years		Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Gross Carrying Value		Accumulated Amortization			Net Carrying Value
Display driver technology		5.3	$	164.0	$	(116.5	)	$	47.5	$	164.0	$	(84.9	)	$	79.1
Audio and video technology		5.5		133.9		(22.8	)		111.1		-		-			-
Fingerprint authentication technology		4.0		55.7		(53.7	)		2.0		63.5		(47.6	)		15.9
Customer relationships		4.1		81.8		(38.5	)		43.3		48.4		(46.0	)		2.4
Licensed technology and other		4.3		9.0		(3.0	)		6.0		1.3		(1.3	)		-
Tradename		7.0		1.9		(0.2	)		1.7		-		-			-
Patents		7.7		4.6		(1.7	)		2.9		4.8		(1.2	)		3.6
Backlog		0.5		0.5		(0.5	)		-		-		-			-
In-process research and development	Not applicable			4.7		-			4.7		-		-			-
Acquired intangibles, gross		5.0	$	456.1	$	(236.9	)	$	219.2	$	282.0	$	(181.0	)	$	101.0

In fiscal 2018, there was $20.1 million of customer relationships, $4.3 million of fingerprint developed technology and $0.1 million patents retired which were fully depreciated. In fiscal 2017, there was $12.1 million of fingerprint developed technology and $22.0 million of supplier arrangements retired, which were fully depreciated.

Amortization expense is calculated using the straight-line method over the estimated useful lives of the acquired intangibles. The total amortization expense for the acquired intangible assets was $83.9 million in fiscal 2018, $59.3 million in fiscal 2017, and $73.0 million in fiscal 2016. This amortization expense was included in our consolidated statements of operations as acquired intangibles amortization and cost of revenue.

The following table presents expected annual aggregate amortization expense in future fiscal years (in millions):

2019	$	74.0
2020		50.5
2021		36.5
2022		32.0
2023		19.5
Thereafter		2.0
To be determined		4.7
Future amortization	$	219.2