-32.1% is the change from 947 to 643
Calculation steps:
[( 643 - 947 ) ÷ 947] x 100 = -32.1%
Formula
Percentage change = [(643 - 947) / 947] x 100
Subtract the new number by the original number
643 - 947 = -304
-304 ÷ 947 = -0.32101372756071805
-0.32101372756071805 x 100 = -32.1%