Question: when was the term leave no trace created
[{'answer': 'in the 1960s and 1970s', 'provenance': [{'wikipedia_id': '276661', 'title': 'Leave No Trace', 'start_paragraph_id': 11, 'start_character': 269, 'end_paragraph_id': 11, 'end_character': 291, 'bleu_score': 1.0, 'section': 'Section::::Origins.\n'}]}, {'provenance': [{'wikipedia_id': '276661', 'title': 'Leave No Trace', 'start_paragraph_id': 11, 'start_character': 0, 'end_paragraph_id': 11, 'end_character': 989, 'bleu_score': 0.9550554505511221, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9687011821247685228}, 'section': 'Section::::Origins.\n'}]}]