The novel coronavirus is an invisible enemy. One of our main weapons is an endless stream of data, but it can often seem confusing.

As society cautiously reopens, how would we know if we were keeping it under control? Here are six numbers to keep a close eye on.

What percentage of tests are positive

Why does that number — ‘test positivity’ — matter?

If too high a number of tests are positive, it suggests that there are a large number of cases in the community that aren’t being found.

If there are, it raises the question: Are we testing enough, in relation to the scale of the problem?

The World Health Organization looks for a number under 10 per cent, though Global News has talked to experts who say that number is arbitrary, and set too low.

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(Whether a place is testing enough is crucial to whether it can afford to reopen: with such a high-stakes decision, the more we know the better.)

Applied to Canada, the graph below seems reassuring, except for Quebec,