Detailed Instructions: This task involves annotating the answer type to a given question that involve some kind of complex reasoning (including numerical reasoning). Note that the questions require looking at more than one part of the passage to answer. There are 3 possible answer types (i) spans, (ii) numbers and (iii) dates. If the answer can be found in the passage, label it as "span". If the answer is a number, label as "number". Similarly, label "date" if you think the answer to the given question is a date.
Q: Passage: Lions quarterback Matthew Stafford threw four interceptions, as Tampa Bay upset Detroit 24-21. The Buccaneers became the first team since 1978 to start the season 0-8 and win their next three games. Stafford was leading the Lions on a potential game-winning or game-tying drive in the final minute. At the Tampa Bay 28 yard line with 1:00 left, Stafford threw to Calvin Johnson at the 3 yard line. Johnson appeared to catch the ball, but it was stripped out and fell into the hands of Johnthan Banks for an interception, and sealed the win for Tampa Bay.
Question: By how many points were the Detroit Lions upset by?
A:
number