function extractRewards (labels: string[], erasRewards: DeriveEraRewards[], ownSlashes: DeriveOwnSlashes[], allPoints: DeriveStakerPoints[], divisor: BN): LineData {
  const slashSet = new Array<number>(labels.length);
  const rewardSet = new Array<number>(labels.length);
  const avgSet = new Array<number>(labels.length);
  const [total, avgCount] = erasRewards.reduce(([total, avgCount], { era, eraReward }) => {