-97.98% is the change from 643 to 13
Calculation steps:
[( 13 - 643 ) ÷ 643] x 100 = -97.98%
Formula
Percentage change = [(13 - 643) / 643] x 100
Subtract the new number by the original number
13 - 643 = -630
-630 ÷ 643 = -0.9797822706065319
-0.9797822706065319 x 100 = -97.98%