<prompt> Translate the following text to EnglishUtafiti huo ulifanywa mnamo Desemba 1998 na ulibadilishwa mnamo Juni 1999 ili kujumuisha data kutoka kwa utafiti wa kitabu cha kitabu cha familia uliofanywa mnamo 1997.  <response>: The paper was presented to the Commission in December 1998 and was revised in June 1999 to include the data from the Household Diary Study conducted in 1997. 