-16.26% is the change from 615 to 515
Calculation steps:
[( 515 - 615 ) ÷ 615] x 100 = -16.26%
Formula
Percentage change = [(515 - 615) / 615] x 100
Subtract the new number by the original number
515 - 615 = -100
-100 ÷ 615 = -0.16260162601626016
-0.16260162601626016 x 100 = -16.26%