Question: when was the r10+20 summit in rio de janeiro held
[{'answer': '13 to 22 June 2012', 'provenance': [{'wikipedia_id': '30480740', 'title': 'United Nations Conference on Sustainable Development', 'start_paragraph_id': 1, 'start_character': 311, 'end_paragraph_id': 1, 'end_character': 329, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'June 2012', 'provenance': [{'wikipedia_id': '30480740', 'title': 'United Nations Conference on Sustainable Development', 'start_paragraph_id': 1, 'start_character': 320, 'end_paragraph_id': 1, 'end_character': 329, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '30480740', 'title': 'United Nations Conference on Sustainable Development', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 561, 'bleu_score': 0.779671160360877, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2332601311708903918}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '30480740', 'title': 'United Nations Conference on Sustainable Development', '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': 2332601311708903918}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '30480740', 'title': 'United Nations Conference on Sustainable Development', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['The United Nations Conference on Sustainable Development (UNCSD), also known as Rio 2012, Rio+20 (), or Earth Summit 2012 was the third international conference on sustainable development aimed at reconciling the economic and environmental goals of the global community. Hosted by Brazil in Rio de Janeiro from 13 to 22 June 2012, Rio+20 was a 20-year follow-up to the 1992 United Nations Conference on Environment and Development (UNCED) held in the same city, and the 10th anniversary of the 2002 World Summit on Sustainable Development (WSSD) in Johannesburg.', 'Hosted by Brazil in Rio de Janeiro from 13 to 22 June 2012, Rio+20 was a 20-year follow-up to the 1992 United Nations Conference on Environment and Development (UNCED) held in the same city, and the 10th anniversary of the 2002 World Summit on Sustainable Development (WSSD) in Johannesburg.']}}]}]