The question is about the blog. The data covers the whole site. Re-crawling just the blog wastes an hour that filtering solves in seconds.
Filtering to the section
Keep the lines starting with the section path. The full crawl becomes a section crawl, and the same export answers questions about any section on demand.
Section-level metrics are the actionable ones
Site-wide averages are almost never useful, because sections differ so much. Separating them shows which template has the problem, and a template fix applies to every page using it.
Keep the original export
One crawl filtered several ways answers more questions than several crawls, and the numbers stay comparable because they all come from the same snapshot. Comparing sections crawled on different days introduces differences that have nothing to do with the sections.
Try it: Keep Lines Starting With on SeoWolf's Notepad.