-17.89% is the change from 615 to 505
Calculation steps:
[( 505 - 615 ) ÷ 615] x 100 = -17.89%
Formula
Percentage change = [(505 - 615) / 615] x 100
Subtract the new number by the original number
505 - 615 = -110
-110 ÷ 615 = -0.17886178861788618
-0.17886178861788618 x 100 = -17.89%