It's a number that compares what you earned and what you have staked, the higher the number the more of a "value extractor" someone is. There is no official guideline of what is too much but I would say everything above 3 starts to get a bit on the high side.

You can check it here (https://beebalanced.streamlit.app/)
You are at 0.95 which is great! Basically, what it comes down to is that right now, there is just way too much free lunch on Hive and many are only really posting, getting curated and cashing everything out. If everyone who curated took KE as a factor into consideration, Hive would likely be much better off as that gives actual incentives for users to buy hive and take care of what they actually contibute.