This is the master collection, containing PDFs of every version and every edition published since the book first went into print in 1997 up until the current year.
As major capital improvements and construction projects were proposed, built and opened, old facilities closed and changes post-9/11 happened you can see them all chronicled in these back editions. Note that the book was only produced in black-and-white until 2020; the 2021 edition was the first time the book was ever made available in color.
These are optimized for screen viewing but are otherwise the exact same files that were sent to the printing presses over the last two decades plus. Print production files were about 275 Mb each, so these are screen versions, and are not printable.