-79% is the change from 643 to 135
Calculation steps:
[( 135 - 643 ) ÷ 643] x 100 = -79%
Formula
Percentage change = [(135 - 643) / 643] x 100
Subtract the new number by the original number
135 - 643 = -508
-508 ÷ 643 = -0.7900466562986003
-0.7900466562986003 x 100 = -79%