I did not get funded, but I submitted 2 years ago to NIMH. The percentage that gets funded is dependent on which institute you are applying to because they each have different budgets. For example, I was told that NIMH expected to fund 20% of the F30 applications. With that being said, I don't know that you are scored separately from F31 and F32 applicants.
I can't remember exactly how scores and percentages work, but they aren't exactly the same. A professor in our department who has been on several study sections explained it to us once. Each study section scores their own set of applications, but some are known for scoring more stringently than others. If I remember correctly, a percentage of each section's grants are funded, meaning that a score of 140 (just as an example, I forget the range and what is considered "good") from one section may be in the top 10% of applications for that section but the same score may only be in the top 30% for another section. Sorry I can't remember the exact details, but I do remember he stressed that the percentile was more important than the score. If I'm wrong, please feel free to correct me.