-5.07% is the change from 670 to 636
Calculation steps:
[( 636 - 670 ) ÷ 670] x 100 = -5.07%
Formula
Percentage change = [(636 - 670) / 670] x 100
Subtract the new number by the original number
636 - 670 = -34
-34 ÷ 670 = -0.050746268656716415
-0.050746268656716415 x 100 = -5.07%