Hi Konstantin,
When you are running a data driven test via Quick Execution, there is dropdown showing the iterations. In order to view the failed/passed/total steps for a specific iteration you need to select that iteration from the dropdown list(see screenshot).
However I agree with you that it will be useful to also have something like a summary showing the sum of all steps from all iterations, so I logged this as a feature request. You can track its progress and vote for it here:
Public URL. We take these votes into account when we determine what to focus on in terms of features.
All the best,
Plamen
the Telerik team