I took my GED in 1997 and I understand that the scoring system has changed since then, so I have three questions...
1. I can tell from the percentile rank that I must have scored pretty well because they were as follows:
science 98,language arts (writing) 99,language arts (reading) 99,social studies 99,math 90
But I understand that ranking is based on a curve compared to other ...ged test takers? or high school graduates?

2. So I'm trying to figure out the percentage based on number of correct answers (to roughly estimate the letter grade equivalent) but I'm not sure how many total questions there were to begin with. My actual scores were: 
science: 71
language arts (writing) 80
language arts (reading) 80
social studies 76
mathematics 63 

3. Last question (but probably the most important one) Do these scores 'expire'? In other words, will I have to retake the GED if I want to go back to school now that it's 2018? 
Deleting Attachment...