Customer | Customer Location | % of total revenues for the year ended December 31, | Trade receivables at December 31, | ||||||||||||||||||||
2017 | 2016 | 2015 | 2017 | 2016 | 2015 | ||||||||||||||||||
A | Taiwan | 17 | % | 29 | % | — | $ | 5,352,000 | $ | 4,870,000 | $ | — | |||||||||||
B | Taiwan | 16 | % | Less than 10% | — | $ | 4,060,000 | $ | — | $ | — | ||||||||||||
C | China | Less than 10% | 15 | % | 14 | % | $ | 246,800 | $ | (100,000 | ) | $ | 1,167,000 | ||||||||||
D | China | — | Less than 10% | 27 | % | $ | — | $ | (3,000 | ) | $ | 3,102,000 | |||||||||||
E | Taiwan | — | — | 16 | % | $ | — | $ | — | $ | 2,222,000 | ||||||||||||