public void AvgMarkSVM()
        {
            MarkSVM = 0;
            var marksList = new List <double>();

            marksList = MarksListSVM();

            if (marksList == null)
            {
            }

            else
            {
                MarkSVM = marksList.Average();
                StudentExamsBySubjectList.Clear();
            }
        }
        public void MaxMarkSVM()
        {
            MarkSVM = 0;

            var marksList = new List <double>();

            marksList = MarksListSVM();

            if (marksList == null)
            {
            }

            else
            {
                MarkSVM = marksList.Max();
                StudentExamsBySubjectList = StudentExamsBySubjectList.FindAll(x => x.Mark == MarkSVM).ToList();
            }
        }