-96.98% is the change from 663 to 20
Calculation steps:
[( 20 - 663 ) ÷ 663] x 100 = -96.98%
Formula
Percentage change = [(20 - 663) / 663] x 100
Subtract the new number by the original number
20 - 663 = -643
-643 ÷ 663 = -0.9698340874811463
-0.9698340874811463 x 100 = -96.98%