We had a similar issue arise in my guild a couple months back.
We use raid attendence to decide tie-breakers on those bidding on items. A newer member had attended nearly every raid since he joined the guild, so his attendence was at nearly 100%. A member that had been in the guild for years had excellent raid attendence too, but not as good as the new member's, or so it seemed. The older member attended 100% of the raids that the new member had since they joined the guild, but they had missed some several months back, so their % was not as good as the newer member. By mistake, the newer member got the item over the old member and chaos ensued.
There needs to be an option for all raid attendence % since DKP started to be tracked for that time period. 30, 60, 90, BC ;p
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Followers of Nobility