-61.64% is the change from 670 to 257
Calculation steps:
[( 257 - 670 ) ÷ 670] x 100 = -61.64%
Formula
Percentage change = [(257 - 670) / 670] x 100
Subtract the new number by the original number
257 - 670 = -413
-413 ÷ 670 = -0.6164179104477612
-0.6164179104477612 x 100 = -61.64%