10 U.S. Code § 4342 - Cadets: appointment; numbers, territorial distribution
authorized strength of the Corps of Cadets of the Academy (determined for any year as of the day before the last day of the academic year) is 4,400 or such lower number as may be prescribed by the Secretary of the Army under subsection (j). Subject to that limitation, cadets are selected as follows:
85 from enlisted members of the Regular Army.
85 from enlisted members of reserve components of the Army.
20 from the honor graduates of schools designated as honor schools by the Department of the Army, the Department of the Navy, or the Department of the Air Force, and from members of the Reserve Officers’ Training Corps.
(citation edited to answer the OP's question)