I don't have a single source, but it is not hard to figure out. Some of it is in MichKa's posts on Google Groups, and notice for example the >1 year long gap be

I don't have a single source, but it is not hard to figure out. Some of it is in MichKa's posts on Google Groups, and notice for example the >1 year long gap between Jet 4.0 SP5 and SP6.