Question: since when has hockey been a regular feature in the olympic games
[{'answer': '1908 Games', 'provenance': [{'wikipedia_id': '3888308', 'title': 'Field hockey at the Summer Olympics', 'start_paragraph_id': 1, 'start_character': 80, 'end_paragraph_id': 1, 'end_character': 90, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3888308', 'title': 'Field hockey at the Summer Olympics', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 185, 'bleu_score': 0.9402297675816911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8815216253446831158}, 'section': 'Section::::Abstract.'}]}]