What is the percentage of requirement bugs that can be found by an inspection team? Low or High?
Can the inspection team find a high number of requirement bugs, or no?
As always, this depends on a number of factors. What type of bugs are you hoping to find. Bugs in the requirements, or functionality that doesn't meet the requirements?
If you're looking for functional bugs based on requirements, of course this can find quite a few. Developers doing a review can find a high ratio of the low hanging fruit that a tester would otherwise be documenting. The same goes for what could be considered vulnerabilities or performance inhibitors. Typically, this number is high, but rarely documented so managers and the like may not see it.
If you're asking about gaps or defects in the requirements, it can help, but, again, depends on numerous factors. One of the largest being the audience of people reviewing. Developers and testers may find a number of requirements gaps when it comes to the classic technical requirements. When it comes to typical business requirements, although a developer may find some gaps, but, this ratio goes up exponentially if they are well versed in the business logic.
To summarize, if reviewed by a cross disciplined group who know what they're doing, the number of bugs avoided is quite high.