http://exams.nachi.org/oe/stats.php (takes a few minutes to open).
Not bad, considering this is a slow market. 
How many passed?
Of the 36234 finished exams:
39% Passed
61% Failed
It looks like a lot of the “others” have taken it. 
Any numbers on our current membership?
Examination Statistics
Since 9/20/2006, thirty-six thousand two hundred and thirty-six people have taken and finished InterNACHI’s Online Inspector Examination. Fourteen thousand one hundred and twenty-six of them passed (about 39%), and twenty-two thousand one hundred and ten failed (about 61%). There are also six thousand eight hundred and thirteen exams that were never finished.
These statistics are recalculated and reposted each time someone finishes InterNACHI’s Online Inspector Examination. Individual statistics for the examination appear as you view each question. The passing grade for this examination is an 80. Examinees have 60 minutes to answer all 120 questions in the exam.
Please note that these statistics were reset on 9/20/2006. Statistics for older versions of the exam are available on the archived stats page.
For more information about the exam, please visit the Examination FAQ.
These are archived statistics for NACHI’s Online Inspector Examination. These statistics apply from 5/29/2006 to 9/20/2006. Older archives are available for before 5/29/2005.
**Total Number of Exams Taken:**12053 (100%)**Total Number of Exams Passed:**3812 (31.63%)**Total Number of Exams Failed:**8241 (68.37%)**Total Number of Unfinished Exams:2044Exams Being Taken Right Now:**N/A **Required Passing Grade:80Average Grade:66.7951Average Passing Grade:85.5711Average Failing Grade:**58.1099
These are archived statistics for NACHI’s Online Inspector Examination. These statistics apply from 1/17/2005 to 5/28/2006. Older archives are available for before 1/17/2005.
**Total Number of Exams Taken:**50539 (100%)**Total Number of Exams Passed:**24529 (48.53%)**Total Number of Exams Failed:**26010 (51.47%)**Total Number of Unfinished Exams:8568Exams Being Taken Right Now:**N/A **Required Passing Grade:75Average Grade:68.4830Average Passing Grade:83.7797Average Failing Grade:**54.0572
These are archived statistics for NACHI’s Online Inspector Examination version 4.0. These statistics apply from the exam’s introduction through 6/2/2004 at 6 PM Eastern Standard Time.
**Total Number of Exams Taken:**23671 (100%)**Total Number of Exams Passed:**12071 (50.99)**Total Number of Exams Failed:**11600 (49.01)**Exams Being Taken Right Now:**2 **Required Passing Grade:75Average Grade:64.12Average Passing Grade:84.11Average Failing Grade:**43.99
How many of those are from the same person?