-18.21% is the change from 615 to 503
Calculation steps:
[( 503 - 615 ) ÷ 615] x 100 = -18.21%
Formula
Percentage change = [(503 - 615) / 615] x 100
Subtract the new number by the original number
503 - 615 = -112
-112 ÷ 615 = -0.1821138211382114
-0.1821138211382114 x 100 = -18.21%