-20.53% is the change from 643 to 511
Calculation steps:
[( 511 - 643 ) ÷ 643] x 100 = -20.53%
Formula
Percentage change = [(511 - 643) / 643] x 100
Subtract the new number by the original number
511 - 643 = -132
-132 ÷ 643 = -0.2052877138413686
-0.2052877138413686 x 100 = -20.53%