I am using the system diagnostics stopwatch to time how long my function takes to run. Currently the output is `0` as it is under `1ms`. How can I record to under a millisecond to 4 decimal places?. I am aware of 'ticks', however I would prefer not to convert ticks to milliseconds for all my timings. 

I am currently using the below code: 

```
System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();
watch.Start();
myFunction();
watch.Stop();
double elapsedTime = watch.ElapsedMilliseconds;   //How to get to 4 decimal places? 
Console.WriteLine("Time " + elapsedTime );

```