It seems hard to find date ranges for what they exactly collect and store, but I found this relevant line that gives 2002 as an upper bounds:

  "More than 99 percent of the 338 specimens from 1917–1969 were completely desiccated, as were over 72 percent of the 218 from 1970–2002."

Also, this gem:

  The JPC does not have documentation regarding any consent forms signed by patients or research participants whose data or specimens were submitted to the repository (Baker personal communication, 2011a). Such consents may have been obtained for clinical procedures used to excise specimens at facilities where people received medical care, but it is highly unlikely that they included notification that the specimens could be sent to a remote repository or used later for education or research purposes. Consents for research use may have been obtained for some materials gathered for the war or cohort registries, but the JPC has no documentation on these (Baker personal communication, 2011a).