Cравнить время, необходимое для выполнения операций с элементами массивов - C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
 
namespace laba1
{
    class Person
    {
        private string name;
        private string secondname;
        private System.DateTime DateOfBirth;
 
        public Person(string name, string secondname, System.DateTime birthday)
        {
            this.name = name;
            this.secondname = secondname;
            this.DateOfBirth = birthday;
        }
        public Person()
        {
            this.name = "Данил";
            this.secondname = "Дегтярев";
            this.DateOfBirth = new DateTime(1996, 11, 10);
        }
        public string NamePro
        {
            get { return name; }
            set { name = value; }
        }
        public string SecondNamePro
        {
            get { return secondname; }
            set { secondname = value; }
        }
        public DateTime DateOfBirthPro
        {
            get { return DateOfBirth; }
            set { DateOfBirth = value; }
        }
        public int YearOfDateTimePro
        {
            get { return DateOfBirth.Year; }
            set { DateOfBirth = new DateTime(value, DateOfBirth.Month, DateOfBirth.Day); }
        }
        public override string ToString()
        {
            return base.ToString() + DateOfBirth.ToString() + secondname.ToString() + name.ToString();
        }
        public string ToShortString()
        {
            return name.ToString() + secondname.ToString();
        }
        static void Main()
        {
 
        }
        
    }
    enum Education { Specialist,Bachelor, SecondEducation}
    class Exam 
    {
        public string objecti{get;set;}
        public int mark{get;set;}
        public System.DateTime DateOfExams{get;set;}
 
        public Exam(string objecti, int mark, System.DateTime DateOfExams)
        {
            this.objecti = objecti;
            this.mark = mark;
            this.DateOfExams = DateOfExams;
        }
        public Exam()
        {
            this.objecti = "english";
            this.mark = 5;
            this.DateOfExams= new DateTime(2016, 01, 15);
        }
        public override string ToString()
        {
            return base.ToString() + objecti.ToString() + mark.ToString() + DateOfExams.ToString();
        }
    }
    class Student
    {
        private Person datastudent;
        private Education FormOfEducation;
        private int  groupnumber;
        private readonly List<Exam> informationExams=new List<Exam>();
 
        public Student()
        {
            this.datastudent = new Person();
            this.FormOfEducation = Education.Bachelor;
            this.groupnumber = 204;
        }
        public override string ToString()
        {
            return base.ToString() + datastudent.ToString() + FormOfEducation.ToString() + groupnumber.ToString();
        }
        public Person Datastudent
        {
            get { return datastudent; }
            set { datastudent = value; }
        }
        public Education formOfEducation
        {
            get { return FormOfEducation; }
            set { FormOfEducation = value; }
        }
        public int groupnumberProp
        {
            get { return groupnumber; }
            set { groupnumber = value; }
        }
 
        public List<Exam> informationExamsPro
        {
            get { return informationExams; }
            
        }
        
        /*public double Srmark
        {
            get { return groupnumber; }
        }
         */
        
        public bool this [Education index]
        {
            get
            {
                if (this.formOfEducation == index)
                    return true; 
                return false;
            }           
        }
        public void AddExams(params Exam[] InfExamsStud)
        {
            informationExams.AddRange(InfExamsStud);
        }
        public override string ToString()
        {
            return base.ToString() + datastudent.ToString() + FormOfEducation.ToString() + groupnumber.ToString() + informationExamsPro.ToString();
        }
    //    //public string ToShortString()
    //    {
    //        return name.ToString() + secondname.ToString();
    //    }
    ////
    }
}