Resolving raid priority

I got an idea last night about how we could handle this. It's basically similar system to epgp but with some changes. First of all, every time you're signed in for a raid, but there's no room your raid priority number increases by 1.

When creating the next raid, those with higher priority get in after the essential classes. This will reduce your priority by 2, because otherwise we'll end up with situations where the real priority is harder to resolve.

However, on top of those 2 things there should also be raid priority depreciation to reward those who are more often online and ready to raid. This means that the priority number would decrease a certain percentage every day or something.

Now the problem with this is execution. It takes simply too much time to manually calculate everything. I tried to find an addon that could store this kind of player data with batch processing and I tried to make it work in Excel, and to some extent I managed, but in the end I realized that if I use Excel it takes too much effort to keep the priority list up to date.

That + other stuff I'm doing to keep stuff updated (GroupCalendar, guild bank, profession list, website and forums in general) simply starts to take its toll, and I am not willing to add these raid priority calculations to my to-do list.

Now, if someone knows a good database application or interface addon that is free of charge and handles this kind of stuff, let me know. Or if you simply can be bothered about keeping these things up do date.

Basically this is the functionality I'm looking for:

- Add a number to character name
- Reduce a number from character name
- Numbers cannot go below 0 (i.e. 5-10 = 0)
- Do percentage change to all the numbers in the system
- Batch processing (numbers can be added / reduced from multiple character names at the same time)
- Sorting the information by priority and character name

Would be huge plus if for example percentage change could be automated, so that the system would automatically reduce each number by 10% once every 48 hours or so.