-29.57% is the change from 913 to 643
Calculation steps:
[( 643 - 913 ) ÷ 913] x 100 = -29.57%
Formula
Percentage change = [(643 - 913) / 913] x 100
Subtract the new number by the original number
643 - 913 = -270
-270 ÷ 913 = -0.29572836801752467
-0.29572836801752467 x 100 = -29.57%