-30.81% is the change from 925 to 640
Calculation steps:
[( 640 - 925 ) ÷ 925] x 100 = -30.81%
Formula
Percentage change = [(640 - 925) / 925] x 100
Subtract the new number by the original number
640 - 925 = -285
-285 ÷ 925 = -0.3081081081081081
-0.3081081081081081 x 100 = -30.81%