Cooldown recovery rate

[Aivan]

Can some1 explain me the math behind map affix less cooldown recovery rate?
I have a map with -63% cdr. I expect my skills to take 63% longer to recover. I have a skill with fixed 9,54(10 unaffected) secs cooldown. On this map it has 27.xx cooldown. Skill which has 3.5 sec had around 9,7 sec cooldown. How are this 63% calculated or is it just a bug?