question: By what year will % of all GaN LEDs be made with gallium-nitride-on-silicon wafers ?
answer: 2020
turker_answer: By 2020 a % of all GaN LEDs will be made with gallium-nitride-on-silicon wafers .
rule-based: % of all GaN LEDs will be made with gallium-nitride-on-silicon wafers by 2020 .