-3.56% is the change from 506 to 488
Calculation steps:
[( 488 - 506 ) ÷ 506] x 100 = -3.56%
Formula
Percentage change = [(488 - 506) / 506] x 100
Subtract the new number by the original number
488 - 506 = -18
-18 ÷ 506 = -0.03557312252964427
-0.03557312252964427 x 100 = -3.56%