Not all arithmetic operations take the same amount of time. Divides and square roots, both performed by the DIV unit, take considerably longer than integer or floating point addition, subtraction, or multiplication. This metric represents cycles fraction where the Divider unit was active.
The DIV unit is active for a significant portion of execution time.
Locate the hot long-latency operation(s) and try to eliminate them. For example, if dividing by a constant, consider replacing the divide by a product of the inverse of the constant. If dividing an integer, consider using a right-shift instead.