(62) However, the imposition of an obligation to provide information is not necessary if the data subject already has the information, if the recording or disclosure of the data is expressly provided for by law, or if informing the data subject proves impossible or would require disproportionate effort. A situation of impossibility or disproportionate effort may arise in particular if the processing serves archival purposes in the public interest, scientific or historical research purposes or statistical purposes. This should take into account the number of data subjects, the duration of data storage and any appropriate safeguards adopted.