-91.57% is the change from 664 to 56
Calculation steps:
[( 56 - 664 ) ÷ 664] x 100 = -91.57%
Formula
Percentage change = [(56 - 664) / 664] x 100
Subtract the new number by the original number
56 - 664 = -608
-608 ÷ 664 = -0.9156626506024096
-0.9156626506024096 x 100 = -91.57%