public function calculateCorrectionTotalGrade(Dropzone $dropzone, Correction $correction)
    {
        $nbCriteria = count($dropzone->getPeerReviewCriteria());
        $maxGrade = $dropzone->getTotalCriteriaColumn() - 1;
        $sumGrades = 0;
        foreach ($correction->getGrades() as $grade) {
            ($grade->getValue() > $maxGrade) ? $sumGrades += $maxGrade : $sumGrades += $grade->getValue();
        }

        $totalGrade = 0;
        if (0 !== $nbCriteria) {
            $totalGrade = $sumGrades / ($nbCriteria);
            $totalGrade = ($totalGrade * 20) / ($maxGrade);
        }

        return $totalGrade;
    }