Staff size question

In Layout Options-Page Setup-Space Size, the staff sizes in millimeters are: 9.2, 7.9, 7.39, 7, 6.51, 6, 5.5, 4.8, and 3.7. The ratios don’t appear to be consistent linear or by proportion. I don’t recall seeing them in any of the notation books I’ve read. Where do the sizes come from?

History and tradition.

Hi @Dissonancely, see Gould (Behind Bars) Pag. 483:

You are correct; it is not linear

We can try to find a function…

You can set the space size to any number you choose, you are not restricted to the defined set of space sizes.

Thank you, everyone, this was informative.