CREATE TABLE table_16054 ("Camp" TEXT, "Estimated deaths" TEXT, "Operational" TEXT, "Occupied territory" TEXT, "Current country of location" TEXT, "Primary means for mass killings" TEXT)

what's the operational period with camp sajmi te
SELECT "Operational" FROM table_16054 WHERE "Camp" = 'Sajmište'
SELECT "Operational" FROM "table_16054" WHERE "Camp" = 'Sajmište'