-97.01% is the change from 670 to 20
Calculation steps:
[( 20 - 670 ) ÷ 670] x 100 = -97.01%
Formula
Percentage change = [(20 - 670) / 670] x 100
Subtract the new number by the original number
20 - 670 = -650
-650 ÷ 670 = -0.9701492537313433
-0.9701492537313433 x 100 = -97.01%