-4.9% is the change from 510 to 485
Calculation steps:
[( 485 - 510 ) ÷ 510] x 100 = -4.9%
Formula
Percentage change = [(485 - 510) / 510] x 100
Subtract the new number by the original number
485 - 510 = -25
-25 ÷ 510 = -0.049019607843137254
-0.049019607843137254 x 100 = -4.9%