ErrorException When i press the button "Statistics" i receive the:

} else { $this->chart['delivered'] = $delivered = $this->stats->delivered_total;

public function calcChart() { if (count($this->stats) > 1) { $this->chart['delivered'] = $delivered = $this->stats->sum('delivered_total'); $this->chart['failed'] = $failed = $this->stats->sum('perm_fail_total'); } else { $this->chart['delivered'] = $delivered = $this->stats->delivered_total; $this->chart['failed'] = $failed = $this->stats->perm_fail_total; } $grandTotal = $delivered + $failed; $factor = $grandTotal / 100; // calc and round the delivered percent to 2 decimal places $this->chart['deliveredPercent'] = $grandTotal ? round($this->chart['delivered'] / $factor, 2) : '--';