From July 23 rd until December 31 st 1942, 713 555 peoples were murdered in Treblinka death camp.
Telegram from deputy commander of Aktion Reinhard, listing number of arrivals in the extermination camps. As we all know the trains were leaving the death camps empty!
Translation:
Letter and 14 day report year-end report 14 day Year 1942 Camp i.d. to 31.12.1942 total L Lublin 12761 24733 B Belzec 0 434508 S Sobibor 515 101370 T Treblinka 10335 713555 * total: 23611 1274166(*) note - in the original reads 71355, but this is probably a typo as 713555 gives the correct total.
see more:
http://hgs.oxfordjournals.org/content/15/3/468.full.pdf+html