-95.37% is the change from 670 to 31
Calculation steps:
[( 31 - 670 ) ÷ 670] x 100 = -95.37%
Formula
Percentage change = [(31 - 670) / 670] x 100
Subtract the new number by the original number
31 - 670 = -639
-639 ÷ 670 = -0.9537313432835821
-0.9537313432835821 x 100 = -95.37%