You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You are also given a question about the story that requires an understanding of the relationship described in the background paragraph and the story. You need to come up with an answer to the given question; the answer will be a span from either the question or the story. In order to correctly answer the given question, you need to understand the relationship mentioned in the background paragraph and should be able to use it to understand that in the story. Your answer can not consist of any word that is not mentioned in any of these: the background paragraph, the story, or the question. You can directly copy and paste a span from the story or the question while answering the given question.
Q: Background Paragraph: Storing large volumes of data – When storing XML to either file or database, the volume of data a system produces can often exceed reasonable limits, with a number of detriments: the access times go up as more data is read, CPU load goes up as XML data takes more power to process, and storage costs go up. By storing XML data in Fast Infoset format, data volume may be reduced by as much as 80 percent. 
Story: Paul had a busy day storing XML. At 3 PM, he stored 22111 Gigabytes to the database. At 4 PM, he stored 33222 Gigabytes to the database. At 5 PM, he stored 44333 Gigabytes to the database. At 6 PM, he got dinner. At 7 PM, he stored 55444 Gigabytes to the database. At 8 PM, he stored 66555 Gigabytes to the database. At 9 PM, he went to sleep to finish storing XML tomorrow afternoon. 
Question: What time did storage costs go up:  5 PM or 6 PM?
A: 
5 PM.