-33.54% is the change from 966 to 642
Calculation steps:
[( 642 - 966 ) ÷ 966] x 100 = -33.54%
Formula
Percentage change = [(642 - 966) / 966] x 100
Subtract the new number by the original number
642 - 966 = -324
-324 ÷ 966 = -0.33540372670807456
-0.33540372670807456 x 100 = -33.54%