Simplify the following text for a Grade 12 native English-speaking person.
Original: Vjekoslav `` Maks '' LuburiÄ , commander-in-chief of all the Croatian camps , announced the great `` efficiency '' of the Jasenovac camp at a ceremony on October 9 , 1942 ( keep in mind that Jasenovac operated until 1945 ) .
Simplified: Vjekoslav `` Maks '' LuburiÄ , commander-in-chief of all the Croatian camps , announced the great `` efficiency '' of the Jasenovac camp at a ceremony as early as 9 October 1942 .