Whenever you configure your executor in the test, you have to set your `Aggregator`. Preferred `Aggregator` is `average`.
If you want to keep the entire set of measurements in `data`, then you have to do `Aggregator.complete(Aggregator.average)`.
I should add the note about that here:

http://axel22.github.com/scalameter//home/gettingstarted/executors/index.html