I don't see a date either, however given some of the dates in the document, it seems sometime between 1997 and 2000.
Relevant lines:
"Representatives from the Organization for Economic Cooperation (OECD) backed the concept of key recovery systems during a January 1997 conference."
"The software industry estimated that, if export controls were removed, US companies could sell as much as $60 billion a year in encryption hardware and software by 2000."