Where is the line-height of lists typo defined in material guideline

This is not a issue or a problem with this repo. Im building my own components (material-design) according https://material.io/guidelines and have some questions!

In the material-design-lite example of e.g. https://getmdl.io/components/index.html#lists-section has the "Primary Text" a font size of 16px and the "Secondary Text" a font size of 14px. This is according Material Guideline (https://material.io/guidelines/components/lists.html#lists-specs) correct.

My question: ~The "Primary text" has a line-height of 20px and the "Secondary text" a line-height of 18px in material-design-lite (e.g. https://getmdl.io/components/index.html#lists-sectio).~ From where you get the line-height´s for Primary and Secondary- Text? Where are this values located in the guidelines (https://material.io/guidelines)?
I found nothing about it in https://material.io/guidelines/style/typography.html and https://material.io/guidelines/components/lists.html#lists-specs !

I hope anyone can help me, thanks.