`mean_success_rate = 0.5` when `num_complete_trials = 1` in benchmark results

Hello,

When I was running the benchmark evaluation, I encountered an unexpected result in the evaluation output. Specifically, for a task where `num_complete_trials` is `1`, the `mean_success_rate` is reported as `0.5`.

Here is the relevant line from the evaluation results:

| Index | Task |num_complete_trials | mean_success_rate | mean_episode_length | total_runtime_s | num_fail_trials |
|-------|--------------------|--------------------|-------------------|---------------------|-----------------|-----------------|
| 114 | TurnOnWifiAndOpenApp | 1 | 0.5 | 13 | 107.6 | 0 |

My understanding is that if `num_complete_trials` is `1`, the `mean_success_rate` should logically be either `0.0` (if the single trial failed) or `1.0` (if the single trial succeeded). A value of `0.5` for a single trial seems contradictory.

Could you please clarify why this might be the case? Is there a specific interpretation or calculation method I'm missing, or could this be an anomaly in the reporting?

Thank you for your time and assistance.