1. What is the lowest SubRating a subtitle may be rated at? 0.0 or 1.0?
2. If a subtitle has not been rated, what is its SubRating? I'm seeing a lot of SubRating = 0.0, so I'm assuming this is the default SubRating.
3. If the answer to question 1 is 0.0, and the answer to question 2 is 0.0, how can we distinguish between the two?