-97.97% is the change from 641 to 13
Calculation steps:
[( 13 - 641 ) ÷ 641] x 100 = -97.97%
Formula
Percentage change = [(13 - 641) / 641] x 100
Subtract the new number by the original number
13 - 641 = -628
-628 ÷ 641 = -0.9797191887675507
-0.9797191887675507 x 100 = -97.97%