<ng-container matColumnDef="from">
    <mat-header-cell *matHeaderCellDef> From </mat-header-cell>
      <mat-cell *matCellDef="let element">
        <tr>{{element.computationrates[0].ratebands[0].from}}</tr>
        <tr>{{element.computationrates[0].ratebands[1].from}}</tr>
        <tr>{{element.computationrates[0].ratebands[2].from}}</tr>
        <tr>{{element.computationrates[0].ratebands[3].from}}</tr>
      </mat-cell>
  </ng-container>