-78.54% is the change from 643 to 138
Calculation steps:
[( 138 - 643 ) ÷ 643] x 100 = -78.54%
Formula
Percentage change = [(138 - 643) / 643] x 100
Subtract the new number by the original number
138 - 643 = -505
-505 ÷ 643 = -0.7853810264385692
-0.7853810264385692 x 100 = -78.54%