Year ended December 31,

2018

2019

2020

NT$000

Gain on disposal of scrapped materials

59,380

43,652

51,077

Royalty income

43,224

12,336

2,962

Gain on disposal of items purchased on behalf of others

31,268

15,080

30,140

Gain on disposal of property, plant and equipment, net

14,274

20,271

48,070

Insurance compensation income

147

10,435

—

Impairment loss on property, plant and equipment

—

(9,938

)

—

Others

(779

)

1,092

3,329

147,514

92,928

135,578