RawFraction performance counter persists its state even after deleting the performance category
private PerformanceCounter mainCounter;
    private PerformanceCounter mainCounterBase;
    private string category = "TestPerformanceCounterTest";
    public void Test()
    {
                   //Counter setup

        if (PerformanceCounterCategory.Exists(category))
            PerformanceCounterCategory.Delete(category);
        if (!PerformanceCounterCategory.Exists(category))
        {
            var categoryCollection = new CounterCreationDataCollection();

            var counter1 = new CounterCreationData("RawCounter1", "", PerformanceCounterType.RawFraction);
            var counter2 = new CounterCreationData("RawCounterBase1", "", PerformanceCounterType.RawBase);
            categoryCollection.Add(counter1);
            categoryCollection.Add(counter2);


            PerformanceCounterCategory.Create(category, "", PerformanceCounterCategoryType.SingleInstance, categoryCollection);

            //  Wait and wait...
            Thread.Sleep(TimeSpan.FromSeconds(3));
        }
                    //create counters
                    mainCounter = new PerformanceCounter(category, "RawCounter1", false);
        mainCounterBase = new PerformanceCounter(category, "RawCounterBase1", false);
                    //reset values
                    mainCounter.RawValue = 0;
        mainCounterBase.RawValue = 0;

                    //update counter
                    mainCounter.IncrementBy(10);
        mainCounterBase.IncrementBy(20);
        **Console.WriteLine("Main counter: " +mainCounter.RawValue);//doesnt show value 50 the second time this is run**
        Console.WriteLine("Main counter Base: " + mainCounterBase.RawValue);
        Console.WriteLine("Main counter next value: " + mainCounter.NextValue());
        Console.WriteLine("Main counter base next value: " + mainCounterBase.NextValue());
    }

while (PerformanceCounterCategory.Exists(category))
{
    PerformanceCounterCategory.Delete(category);
}