Albert Barnes Commentary Ezra 8:35

"The children of the captivity, that were come out of exile, offered burnt-offerings unto the God of Israel, twelve bullocks for all Israel, ninety and six rams, seventy and seven lambs, twelve he-goats for a sin-offering: all this was a burnt-offering unto Jehovah." — Ezra 8:35 (ASV)

Compare the marginal reference. The idea of offerings for all Israel pervades in this case the entire sacrifice, with the exception of the lambs, whose number (77) is unique, and has not been accounted for.