Detailed Instructions: This task involves creating answers to complex questions, from a given passage. Answering these questions, typically involve understanding multiple sentences. Make sure that your answer has the same type as the "answer type" mentioned in input. The provided "answer type" can be of any of the following types: "span", "date", "number". A "span" answer is a continuous phrase taken directly from the passage or question. You can directly copy-paste the text from the passage or the question for span type answers. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words. A "number" type answer can include a digit specifying an actual value. For "date" type answers, use DD MM YYYY format e.g. 11 Jan 1992. If full date is not available in the passage you can write partial date such as 1992 or Jan 1992. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words.
Q: Passage: Tampa Bay hosted Chicago at Wembley Stadium in London, England, their second time participating in the NFL International Series. Josh Freeman threw four interceptions, and Tampa Bay lost one fumble for five total turnovers. Chicago stretched out to a 21-5 lead before the Buccaneers staged a rally in the fourth quarter. Freeman threw two touchdown passes and the deficit was trimmed to 24-18 in the final two minutes. Freeman drove the Buccaneers to the Chicago 39-yard line, but the comeback was thwarted when he was intercepted with 37 seconds left. Running back LeGarrette Blount was inactive due to injury, and Earnest Graham left the game in the first quarter due to an ankle injury. Third-string running back Kregg Lumpkin was left to handle rushing duties, but managed only 15 yards.
Question: How many points did Chicago lead by to win?
Answer type: Number
A:
6.