public double getAverageResponseTime() { if (timerReviews == null) { timerReviews = new ReviewList(); for (Student student : StudentManager.instance().values()) { if (student.getGradingGroup() != GradingGroup.SCORE) continue; ReviewList tempList = student.getReviewsClone(); for (int i = 0; i < tempList.size(); i++) timerReviews.add(tempList.get(i)); } } return timerReviews.getFor(this).getAverageResponseTime(); }