Data structure performance test

static class Program
{
    [STAThread]
    static void Main()
    {
        int times = 100000;
        Console.WriteLine("Testing performance of adding " + times + " integers to different data structures...");
        Console.WriteLine();
        Random r = new Random();
        List<int> optimisedL = new List<int>();
        SkipList<int> list = new SkipList<int>();
        AvlTree<int, int> tree = new AvlTree<int, int>();
        Stopwatch watch = new Stopwatch();
        watch.Start();
        for (int i = 0; i < times; i++)
        {
            int rand = r.Next(100000);
            AddToSortedList(optimisedL, rand);
        }
        watch.Stop();
        double listTime = watch.Elapsed.TotalSeconds;
        Console.WriteLine("Sorted list: " + listTime);
        watch.Reset();
        watch.Start();
        for (int i = 0; i < times; i++)
        {
            int rand = r.Next(100000);
            list.Add(rand);
        }
        watch.Stop();
        double skipListTime = watch.Elapsed.TotalSeconds;
        Console.WriteLine("Skip list:   "+skipListTime);
        watch.Reset();
        watch.Start();
        for (int i = 0; i < times; i++)
        {
            int rand = r.Next(100000);
            tree.Insert(rand, rand);
        }
        watch.Stop();
        double treeTime = watch.Elapsed.TotalSeconds;
        Console.WriteLine("AVL tree:    "+treeTime);

        Console.WriteLine("DONE");
        Console.ReadKey();
    }

    private static void AddToSortedList(List<int> sortedList, int item)
    {
        int min = 0;
        int max = sortedList.Count;
        int index = 0;
        while (min < max)
        {
            index = (min + max) / 2;
            if (item < sortedList[index])
            {
                min = index + 1;
                index = min;
            }
            else
            {
                if (item > sortedList[index])
                {
                    max = index;
                    index = max;
                }
                else
                    break;
            }
        }
        sortedList.Insert(index, item);
    }
}