Web服务单元测试性能

Question

我很想知道为什么连续调用Web服务方法执行得更快（每次调用），调用次数越多或执行次数越多;根据单元测试执行时间...

public void Test_CardActivationWebService(string cardNo)
    {
        bool expected = true;
        bool actual = false;

        ServiceReference1.FDH_WSClient iclfdhws = new ServiceReference1.FDH_WSClient();
        ServiceReference1.CardActivationResponse response = iclfdhws.CardActivation(cardNo);
        actual = response;

        Assert.AreEqual(expected, actual);
    }