Graduation - Part. 2 [C#]

using System;

namespace GraduationPart2
{
    class Program
    {
        static void Main(string[] args)
        {
            string name = Console.ReadLine();
            double currentYear = 1;
            double gradeTotal = 0;
            double currentGrade = 0;
            int counter4 = 0;

            bool isExcluded = false;

            while (currentYear <= 12)
            {
                currentGrade = double.Parse(Console.ReadLine());

                if (currentGrade < 4)
                {
                    counter4++;
                }

                else
                {
                    gradeTotal += currentGrade;
                    currentYear++;
                }

                if (counter4 > 1)
                {
                    isExcluded = true;
                    break;
                }
            }

            if (!isExcluded)
            {
                double averageGrade = gradeTotal / 12;
                Console.WriteLine($"{name} graduated. Average grade: {averageGrade:F2}");
            } else {
                Console.WriteLine($"{name} has been excluded at {currentYear} grade");
            }
        }
    }
}