-38.88% is the change from 643 to 393
Calculation steps:
[( 393 - 643 ) ÷ 643] x 100 = -38.88%
Formula
Percentage change = [(393 - 643) / 643] x 100
Subtract the new number by the original number
393 - 643 = -250
-250 ÷ 643 = -0.38880248833592534
-0.38880248833592534 x 100 = -38.88%