OOP) Grades Analyser version 2

import java.util.ArrayList;

public class GradeAnalyzer {

    public GradeAnalyzer (){

    }

    public int getAverage (ArrayList<Integer> grades){
        if (grades.size() < 1){
            System.out.println("Error! You have no grades yet!");
            return 0;
        } else {
            int sum = 0;
            for (int i =0 ; i<grades.size();i++){
                sum = sum + grades.get(i);
            }

            int average = sum / grades.size();
            return average;

        }
    }


    public static void main(String[] args) {
        ArrayList<Integer> my5thClassroom = new ArrayList<>();

        my5thClassroom.add(98);
        my5thClassroom.add(92);
        my5thClassroom.add(88);
        my5thClassroom.add(75);
        my5thClassroom.add(61);
        my5thClassroom.add(89);
        my5thClassroom.add(95);

       GradeAnalyzer my5thAnalyser = new GradeAnalyzer();
       int my5thAver = my5thAnalyser.getAverage(my5thClassroom);

       System.out.println("The average of your 5th Grade grades is: " + my5thAver);

       ArrayList<Integer> my6thClassroom = new ArrayList<>();

       my6thClassroom.add(67);
       my6thClassroom.add(99);
       my6thClassroom.add(75);
       my6thClassroom.add(99);
       my6thClassroom.add(99);

       GradeAnalyzer my6thAnalyser = new GradeAnalyzer();

       int my6thAver = my6thAnalyser.getAverage(my6thClassroom);
       System.out.println("The average of your 6th Grade grades is: " + my6thAver);

       if (my5thAver > my6thAver){
           System.out.println("5th Grade is doing better than 6th Grade");
       }else{
           System.out.println("6th Grade is doing better than 5th Grade");
       }
    }
}