Question: when did to kill a mockingbird become popular
[{'answer': '1960', 'provenance': [{'wikipedia_id': '73408', 'title': 'To Kill a Mockingbird', 'start_paragraph_id': 1, 'start_character': 60, 'end_paragraph_id': 1, 'end_character': 64, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '73408', 'title': 'To Kill a Mockingbird', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 437, 'bleu_score': 0.705743103035659, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5999087938704648842}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '73408', 'title': 'To Kill a Mockingbird', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5999087938704648842}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '8355369', 'title': 'List of To Kill a Mockingbird characters', 'section': 'Section::::Primary characters.:Atticus Finch.\n', 'start_paragraph_id': 4, 'end_paragraph_id': 4, 'meta': {'evidence_span': ['Harper Lee\'s "To Kill a Mockingbird" was published in 1960.', 'Harper Lee\'s "To Kill a Mockingbird" was published in 1960.', 'Harper Lee\'s "To Kill a Mockingbird" was published in 1960. Instantly successful, widely read in high schools and middle schools in the United States, it has become a classic of modern American literature winning the Pulitzer Prize.']}}]}, {'provenance': [{'wikipedia_id': '57858983', 'title': 'To Kill a Mockingbird (2018 play)', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['To Kill a Mockingbird is a 2018 play based on the 1960 novel of the same name by Harper Lee, adapted for stage by Aaron Sorkin. It opened on Broadway at the Shubert Theatre on December 13, 2018.', 'To Kill a Mockingbird is a 2018 play based on the 1960 novel of the same name by Harper Lee, adapted for stage by Aaron Sorkin. It opened on Broadway at the Shubert Theatre on December 13, 2018', 'To Kill a Mockingbird is a 2018 play based on the 1960 novel of the same name by Harper Lee, adapted for stage by Aaron Sorkin. It opened on Broadway at the Shubert Theatre on December 13, 2018.']}}]}, {'provenance': [{'wikipedia_id': '73408', 'title': 'To Kill a Mockingbird', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['To Kill a Mockingbird is a novel by Harper Lee published in 1960. Instantly successful, widely read in high schools and middle schools in the United States, it has become a classic of modern American literature, winning the Pulitzer Prize.', 'To Kill a Mockingbird is a novel by Harper Lee published in 1960.', 'To Kill a Mockingbird is a novel by Harper Lee published in 1960. Instantly successful, widely read in high schools and middle schools in the United States, it has become a classic of modern American literature, winning the Pulitzer Prize.']}}]}]