Which means 85% of the cases where asylum is granted are fraudulent.
No, the statistic quoted in support of the claim is based on only 15% being granted. I think, though, calling all invalid asylum claims "fraudulent" is overstating it, some invalid claims are fraudulent, others a result of an erroneous reading of the law, or of presenting insufficient evidence for the immigration court to rule in favor of what, if well-supported would have been a valid claim, still others of those denied were denied in error.
Your assertion is also statistically ill-founded. The rate of false positives (in this case invalid claims erroneously granted by the court) is not the same as the rate of negatives (both true and false, in this case claims denied whether correctly or incorrectly), indeed in general the two are unrelated.
