Data releases
A data release freezes the statistics at one moment: exactly which records count, and an archive of their facts with a checksum. Results computed on a release can be cited and re-run later with the identical result. Results on the live data are provisional and change as records are added or corrected.
No data release has been published yet. Until then every number on this site is provisional.
How a re-run works: the stored query is computed again on the archived facts of the release instead of the live ones, and the checksum of the new result is compared with the stored one.