-79.85% is the change from 670 to 135
Calculation steps:
[( 135 - 670 ) ÷ 670] x 100 = -79.85%
Formula
Percentage change = [(135 - 670) / 670] x 100
Subtract the new number by the original number
135 - 670 = -535
-535 ÷ 670 = -0.7985074626865671
-0.7985074626865671 x 100 = -79.85%