Question: how many seasons of blue heelers are there
[{'answer': '13', 'provenance': [{'wikipedia_id': '881128', 'title': 'Blue Heelers', 'start_paragraph_id': 3, 'start_character': 235, 'end_paragraph_id': 3, 'end_character': 237, 'bleu_score': 1.0, 'section': 'Section::::Overview.\n'}]}, {'provenance': [{'wikipedia_id': '881128', 'title': 'Blue Heelers', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 425, 'bleu_score': 0.9304844600065421, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12764459678299136295}, 'section': 'Section::::Overview.\n'}]}]