-33.44% is the change from 966 to 643
Calculation steps:
[( 643 - 966 ) ÷ 966] x 100 = -33.44%
Formula
Percentage change = [(643 - 966) / 966] x 100
Subtract the new number by the original number
643 - 966 = -323
-323 ÷ 966 = -0.33436853002070394
-0.33436853002070394 x 100 = -33.44%