Fix Division Guard

The model receives the prompt (and optional system message). The run uses scorer contains_all with the JSON configuration below. Pass/fail and partial credit are determined entirely by that scorer against the model output; no human grading.

Fix the bug and return corrected Python code only.

def success_rate(success, total):
    return round((success / total) * 100, 2)

{
  "expected_contains": [
    "if total == 0",
    "return 0",
    "round((success / total) * 100, 2)"
  ]
}