How can I tell how many construction robots I have?

[pf_moore]

As far as I can see, "Available Robots" is about logistic robots. But I don't see a way to work out how many construction bots I have (short of waiting till I have no construction projects on the go, and no repairs under way, and checking in each of my roboports...)

[ssilk]

Not available yet.

[jeroon]

Today i noticed that construction bots are being added to the "Available robots" totals count while they're constructing something, as soon as they're done, the number drops back to the total number of logistic bots.