Not much, the Zs values have come down a tad as Jay says. If you want to know what has changed then if you look through the regs, you will see a black line on the right side of the page next to certain things, this indicates that it is a change, an addition to the regs, or has been moved from elsewhere in the previous edition. This black line can run the full length of the page or can appear as vertical dotted line. As an example if you look at the green regs page 233 the line runs the full length of the page, so this page was added/changed/moved to the last edition. Page 113 has only one small line.
Cheers............Howard