-38.72% is the change from 643 to 394
Calculation steps:
[( 394 - 643 ) ÷ 643] x 100 = -38.72%
Formula
Percentage change = [(394 - 643) / 643] x 100
Subtract the new number by the original number
394 - 643 = -249
-249 ÷ 643 = -0.38724727838258166
-0.38724727838258166 x 100 = -38.72%