BistroDriveWebApp.Models.UserRepository.UpdateUserRaiting C# (CSharp) Method

        private void UpdateUserRaiting(string Id_User)
        {
            var user = context.reviews.Where(rev => rev.Id_User == Id_User);
            aspnetuser d = GetUserById(Id_User);
            if (user.Count() != 0)
            {
                double average = (double)user.Average(rev => rev.Mark);
                d.Raiting = Convert.ToInt32(Math.Round(average, 0));
            }
            else
            {
                d.Raiting = 0;
            }
            context.SaveChanges();
        }