-20.68% is the change from 643 to 510
Calculation steps:
[( 510 - 643 ) ÷ 643] x 100 = -20.68%
Formula
Percentage change = [(510 - 643) / 643] x 100
Subtract the new number by the original number
510 - 643 = -133
-133 ÷ 643 = -0.20684292379471228
-0.20684292379471228 x 100 = -20.68%