So how accurate is the miningpoolhubstats page?

I am just mining straight Zcash.  My rig shows 3.3 KH/s average.  When I check the stats page it says it is 2.3 KH/s average.  It has been running for a week straight and that is the 24 hour value.  Not sure why there would be such a difference. 

I am using Awesome miner with DSTM miner.  Any ideas?

Thanks for any help