This is not necessarily bad performance. When I did the test 3 years ago I answered only on 51 questions (with at least 1 mistake that I know of) and got
860 (91%). Good luck!!
Well, I'm an international student with what I would say a below average profile (I only started doing mathematics last year, after switching from physics, and didn't do well in my first semester as a math student). I was banking on the subject GRE to mitigate my profile, and in the two practice tests I could get my hands on I scored 850-860 (that's 89% according to 2011-14 data). And that was with me leaving out only 3-4 questions and getting 7-8 wrong (I didn't take any guesses, all these were silly mistakes). I was hoping that with some luck I might be able to push myself to 95%, to possibly get a favorable point rather than a passable score. But in the actual test I straight out left 4 questions without even reading them, I know I have got 3 wrong and have taken a couple of guesses. With the inevitable (additional) 7-8 wrongs I'll most probably get, GRE is not going to strengthen my profile, and in worst case scenario, it might even be an additional thorn in my side