As far as I know it's all based on data generated by 7Sage's analytics. I'm more certain it's the case for the percentages than for the difficulty ranking as the latter could have been assigned by JY et al.
... Premise (strengthening causation): the fish recover normal hormone concentrations relatively quickly ... first premise (the fish recover normal hormone concentrations relatively quickly ... explains why the fish recover normal hormone concentrations relatively ...
(E) There are ways slanted interpretations of data can be removed other than just through careful review by scientists who share the biases of the author or authors of the papers.
You don't have enough data to go on to warrant stopping for drilling. Add in an LG section as a fifth section and you should be good to go for the time being. I find LG to be pretty fun so I will just do a random section whenever I have time.