Actually I haven't passed PMP certification exams but can provide some information.
By the way look what management trainer of PMP say about passing score and percentage of people
succeed in PMP Certification:
Dr. Paul D. G.Develop and Deliver Graduate Level,Program and Project Management:
"I have been running PMP (and other cert) prep courses for 20 plus years and we have a 16 year running first attempt pass rate for English as Second Language (ESL) mid career path professionals of 86% and for native/near native speakers of 99%+.As with anything else like this, commitment is the key. It takes best case, 80 hours of honest study, worst case of 200 hours and a most likely of 120 hours to achieve sufficient understanding to be able to pass.
I stick by my earlier statement that the passing SCORE (as opposed to the passing RATE) was and remains at 106/175 correct or about 62%.What has been explained to me by credible and respected people in the PMI organization is the organization has adjusted the passing SCORE to ensure that about 70% of those taking the exam pass it."