Heres an easy way to figure your NSS...
take your grade on the FRR exam in API and divide it by your current PRT score, then take the sum of all your CPT grades and multiply it by the number of 4's you get on FAM 7, then subract your grade on the flight line drivers course exam from 49.5 and add it to the current total, finally take this and multiply by your onwings LT ranking and you should have a pretty good idea of how your doing