-3.31% is the change from 665 to 643
Calculation steps:
[( 643 - 665 ) ÷ 665] x 100 = -3.31%
Formula
Percentage change = [(643 - 665) / 665] x 100
Subtract the new number by the original number
643 - 665 = -22
-22 ÷ 665 = -0.03308270676691729
-0.03308270676691729 x 100 = -3.31%