How does coverage json work in chrome?

Question

css

I made an import in coverage in JSON, there are indicated not used or used parts in the CSS file, I did not understand which ones. There is complete nonsense.
Here is the correct data https://yadi.sk/i/XF8eZ5vb4bBdDg , but in json I don’t understand what is indicated

{
        "start": 19,
        "end": 51
      },
      {
        "start": 53,
        "end": 179
      },

is it characters or strings? and so and so checked these data do not coincide with the fact that on the screen above and does not match in meaning, there is complete nonsense. I didn't understand how it works. In the coverage itself, everything is correctly indicated.