-96.91% is the change from 647 to 20
Calculation steps:
[( 20 - 647 ) ÷ 647] x 100 = -96.91%
Formula
Percentage change = [(20 - 647) / 647] x 100
Subtract the new number by the original number
20 - 647 = -627
-627 ÷ 647 = -0.9690880989180835
-0.9690880989180835 x 100 = -96.91%