The records that got purged from the factory, I believe, were just hardcopies of individual cars. The SG-30 Options & Accessories reports were something completely different. A full report was printed off at the end of the production year to give the product planners an idea of what options were popular, and what options were not popular. These reports didn't show actual numbers, they showed installation rates (percentages). And these percentages were rounded to the nearest tenth of a percent. So when you take this rounded percentage figure and multiply it times the actual production figures for a certain model of car, you get an estimate of how many cars came with said option. If you are really interested in the details, I have a write up (SG-30 Tutorial) posted to my Mopar Sunroof Registry site that goes through this production number stuff:
https://moparsunroofregistry.files.wordpress.com/2016/09/sg30_explaination2.pdf
