I'm sure someone can answer better than I can, but I'll try.
You're score is based on whether you're applying for NCM or Officer.
I scored 78th percentile for NCM (my score was better than 78% of people applying for NCM trades) but my score was 38th percentile for Officer (I scored better than 38% of people applying for Officer trades).
There's cutoffs for certain trades, and you're ranked against other applicants, but the personality score and interview score play a role also. The CFAT holds the most weight though.