In the [Paper](http://arxiv.org/abs/2005.11856) and the [README.md](https://github.com/mlmed/covid-severity#readme), the total **opacity score** ranged from 0 to 6. Why, in the [Ralo-Dataset](https://github.com/mlmed/covid-severity/blob/master/RALO-Dataset.zip), does the **opacity score** range from 0 to 8?