The intensification of the traffic in “illegal” immigrants, which was resumed on substantial scale toward the end of 1945, made it impossible for the Administration fully to apply its system of preferential categories. In the period between the 15th of December 1945, and the 14th of March 1947, no less than 13,989 illegal Jewish immigrants were permitted to settle in Palestine; an equivalent number was accordingly deducted from the quotas.
Source: The Political History of Palestine under British Administration Published (by His Britannic Majesty’s Government presented in July, 1947, to the United nations Special Committee on Palestine) Published at Jerusalem 1947 (pg 42)