Ok, what about this? But we'll do it for all guilds then, starting from level 1 till level 8:
Guild doesn't loose EXP at all, but, if guild doesn't obtain required amount within 1 week (from Mon till Sun), guild is going to be removed from the Ranking list for the next week. If guild gains needed amount next week - it returns back to the Ranking list.
Guild needs to gain the following amount of EXP within a week if they want to stay in the Ranking list next week:
level 1 - 1000 EXP
level 2 - 2000 EXP
level 3 - 3000 EXP
level 4 - 4000 EXP
level 5 - 5000 EXP
level 6 - 6000 EXP
level 7 - 7000 EXP
level 8 - 8000 EXP
...
This is much better.