You'd be welcome to change those numbers if you think it makes sense.Yeh not a problem - but 1/10th of the time and 1/10th of the money looked a bit too neat of a correlation especially seeing them following on on the next line, plus thinking of sails and cannons I thought pretty much the same time on and off since they are replacements BUT if you factor in ordering them and getting them made it makes more sense. I suspect copper sheeting however may be pretty much the same on and off (plus making good) but it it doesn't really matter.
I have no loyalty to those "tens".