A copy or excerpt of a document may be admitted as evidence if the original is not readily available and if authenticity is established by competent evidence. When numerous or duplicative documents are offered, the examiner may limit those admitted to a number of documents which are typical and representative. The examiner may require the offering party to abstract or summarize relevant data from documents and present the abstracts or summaries in exhibit form. All parties shall have the right to examine the documents abstracted or summarized.