Original: He is both the youngest (43 years old) and the oldest (74 years old) person to have held the position, as well as the only person to have held the position for two non-consecutive terms, and the second longest serving, behind Robert McNamara.
Simplified: He is both the youngest (43 years old) and the oldest (74 years old) person to have held the position, as well as the only person to have held the position for two non-consecutive terms.