-21.91% is the change from 648 to 506
Calculation steps:
[( 506 - 648 ) ÷ 648] x 100 = -21.91%
Formula
Percentage change = [(506 - 648) / 648] x 100
Subtract the new number by the original number
506 - 648 = -142
-142 ÷ 648 = -0.2191358024691358
-0.2191358024691358 x 100 = -21.91%