It's the ratio that space itself expands per second. Each second, space expands by a multiple of 1 + (74 km / 1 megaparsec).
If the humans are actually trying to prove their human-ness (like they get a prize for convincing others that they are human), then I cannot believe how any bot can get >1%. I see these articles a lot over the last few years, and every time the bots fail to simple contextual questions and general conversation flow.
That the winning bot got 30% tells me that the humans in this experiment were not trying their hardest to appear human, and I don't see the point of a Turing test where this is the case.
TFA links to the actual list that Oracle claims, why isn't this in the summary so that people can judge for themselves:
I don't see why this is news though. Marketing department chooses a convenient level of granularity to get a shiny number. Isn't that like, all marketing?