x_points[first_ti.task_id].append(date_time)
                fails_dict_key = (first_ti.dag_id, first_ti.task_id, first_ti.run_id)
                fails_total = fails_totals[fails_dict_key]
                y_points[first_ti.task_id].append(float(duration + fails_total))
        cumulative_y = {k: list(itertools.accumulate(v)) for k, v in y_points.items()}
        
        
        y_unit = infer_time_unit([d for t in y_points.values() for d in t])
        cum_y_unit = infer_time_unit([d for t in cumulative_y.values() for d in t])
        
        chart.create_y_axis("yAxis", format=".02f", custom_format=False, label=f"Duration ({y_unit})")
        chart.axislist["yAxis"]["axisLabelDistance"] = "-15"
        cum_chart.create_y_axis("yAxis", format=".02f", custom_format=False, label=f"Duration ({cum_y_unit})")
        cum_chart.axislist["yAxis"]["axisLabelDistance"] = "-15"
        for task_id in x_points:
            chart.add_serie(
                name=task_id + "[]" if task_id in mapped_tis else task_id,
                x=x_points[task_id],
                y=scale_time_units(y_points[task_id], y_unit),
            )
            cum_chart.add_serie(
                name=task_id + "[]" if task_id in mapped_tis else task_id,
                x=x_points[task_id],
                y=scale_time_units(cumulative_y[task_id], cum_y_unit),
            )
        max_date = max((ti.execution_date for ti in task_instances), default=None)
        session.commit()
        form = DateTimeWithNumRunsForm(
            data={
                "base_date": max_date or timezone.utcnow(),