Do I need all the updates, or just the most recent?

I'm in the process of cleaning out my hard drive to free up some extra space. In my add/remove programs menu I have "J2SE Runtime Environment 5.0" updates 3, 4, 6, 8, and 9. Do I need to keep all of these, or only the most recent one? I could free up almost half a gigabyte if I delete the older ones, but I don't want to do so and then find out that I screwed up my computer. So my question is, do the new updates simply compliment the old ones, or replace them entirely? Can I safely remove updates 3, 4, 6, and 8?

[525 byte] By [bwh79a] at [2007-10-3 11:20:56]