Question: in which year was the first world environmental day celebrated
[{'answer': '1974', 'provenance': [{'wikipedia_id': '1838622', 'title': 'World Environment Day', 'start_paragraph_id': 1, 'start_character': 208, 'end_paragraph_id': 1, 'end_character': 212, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1838622', 'title': 'World Environment Day', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 705, 'bleu_score': 0.83087281288917, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1852353430623802702}, 'section': 'Section::::Abstract.'}]}]