Question: when did pretty little liars season 7 start
[{'answer': 'June 21 , 2016', 'provenance': [{'wikipedia_id': '49091814', 'title': 'Pretty Little Liars (season 7)', 'start_paragraph_id': 62, 'start_character': 760, 'end_paragraph_id': 62, 'end_character': 774, 'bleu_score': 1.0, 'section': 'Section::::Production.:Development.\n'}]}, {'provenance': [{'wikipedia_id': '49091814', 'title': 'Pretty Little Liars (season 7)', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 547, 'bleu_score': 0.9796927878356411, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8228869158078845230}, 'section': 'Section::::Abstract.'}]}]