Does "for" in .Net Framework 4.0 execute loops in parallel? Or why is the total not the sum of the parts

I am writing 开发者_如何学Pythoncode to performance test a web site. I have the following code:

        string url = "http://xxxxxx";
        System.Diagnostics.Stopwatch stopwatch = new System.Diagnostics.Stopwatch();

        System.Diagnostics.Stopwatch totalTime = new System.Diagnostics.Stopwatch();
        totalTime.Start();

        for (int i = 0; i < 10; i++)
        {
            stopwatch.Start();
            WebRequest request = HttpWebRequest.Create(url);
            WebResponse webResponse = request.GetResponse();
            webResponse.Close();
            stopwatch.Stop();
            textBox1.Text += "Time Taken " + i.ToString() + " = " + stopwatch.Elapsed.Milliseconds.ToString() + Environment.NewLine;
            stopwatch.Reset();

        }

        totalTime.Stop();
        textBox1.Text += "Total Time Taken = " + totalTime.Elapsed.Milliseconds.ToString() + Environment.NewLine;

Which is giving the following result:

Time Taken 0 = 88
Time Taken 1 = 161
Time Taken 2 = 218
Time Taken 3 = 417
Time Taken 4 = 236
Time Taken 5 = 217
Time Taken 6 = 217
Time Taken 7 = 218
Time Taken 8 = 409
Time Taken 9 = 48
Total Time Taken = 257

I had expected the total time to be the sum of the individual times. Can anybody see why it is not?

Use TotalMilliseconds instead of Milliseconds and try your test again. Your results aren't what you think they are.