Estimated time to find a new block is 100% - less than this means your pool was lucky so you get in shorter time the same profit, above 100% means your pool was not lucky and it took longer to find new block so your profit is less.
e.g. you could mine 1 DBIX per day @ 100%, if your average variance is 200% you would just get 0.5 DBIX, if your average variance is 50% you would get 2.0 DBIX

of course there are other dependencies too like if you are on PPLNS with low value and you are somewhere far at the bottom of the miner list with poor mining power, ....