Like in the intro, it's quite easy to count HTTP codes
to discover, at the time of writing that most of the XML sitemap URLs are actually redirects...
Plot the years the pages were added
You might have noticed that in this XML sitemap with a "lastmod" field. This is an optional field that explicitly declares to Google last modification date. This allows theoretically Google to optimise website crawls.
It also allows us to understand how fresh is one's website content as we can plot it