It's not worth knowing exact cable-pull stats, IMO. You just need to know which things are compatible. As long as you know that 8-speed D/A will only work (indexing) with 8-speed D/A, and all other Shimano (including 9- and 10-speed D/A, not 7- or 8-speed) will work with each other, then you're good to go.
Sheldon has a compatibility article
http://www.sheldonbrown.com/speeds.html