A crawl covers the entire site. The question is only about the blog, or only about product pages, and everything else is noise obscuring the answer.
Narrowing to the section
Keep only the URLs matching the section's path pattern. Forty thousand rows become the four thousand that the question is actually about.
Why sections need separate analysis
Site-wide averages hide the problems worth finding. A site averaging a 2-second load time might have a blog at 1.1 seconds and product pages at 4.8. The average is a number nobody can act on; the split is a priority.
Compare sections rather than pages
Once each section is isolated, the same metric across sections shows where effort belongs. That comparison consistently produces clearer decisions than ranking individual pages, because sections usually share a template and a template fix is one job for thousands of pages.
Try it: Keep Lines Matching Regex on SeoWolf's Notepad.