The pictures you posted are for FB usage, and in that case that graph going up and down is normal. I believe what you should be more concerned about is how your hash rate is going? Do you also have problems with your hash rate going up or down? If its at a constant 20-23 MH then you should be fine. Don't worry too much as long as your rigs are stable mining and not crashing.
I have no issue with hashrate, it say constantly at 21.5-22.5
I have 2 card in my rig and the power varies from 180-200w pretty unstable.