Question: when did def leppard release their first album
[{'answer': '14 March 1980', 'provenance': [{'wikipedia_id': '174857', 'title': 'Def Leppard', 'start_paragraph_id': 12, 'start_character': 67, 'end_paragraph_id': 12, 'end_character': 80, 'bleu_score': 1.0, 'section': 'Section::::History.:Rise to fame (1980–1983).\n'}]}, {'provenance': [{'wikipedia_id': '174857', 'title': 'Def Leppard', 'start_paragraph_id': 12, 'start_character': 0, 'end_paragraph_id': 12, 'end_character': 1098, 'bleu_score': 0.9636844770794871, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17250539498088746698}, 'section': 'Section::::History.:Rise to fame (1980–1983).\n'}]}]