-95.17% is the change from 642 to 31
Calculation steps:
[( 31 - 642 ) ÷ 642] x 100 = -95.17%
Formula
Percentage change = [(31 - 642) / 642] x 100
Subtract the new number by the original number
31 - 642 = -611
-611 ÷ 642 = -0.9517133956386293
-0.9517133956386293 x 100 = -95.17%