20 hour space expeditions

[Kaotik]

(08-05-2015, 07:44 AM)Wq9ill Wrote: 4 hours: 50%
8 hours: 100%
20 hours: 150%

Yes, I know what it says...
What I was asking, is why do you only get 150% for the 20 hour expedition? If 8 hours is 100%, and 4 hours is 50% (50% of 8 hours = 4 hours) so that makes sense. But, 20 hours is 250% of 8, so, why don't you get 250% of the reward?