-77.41% is the change from 509 to 115
Calculation steps:
[( 115 - 509 ) ÷ 509] x 100 = -77.41%
Formula
Percentage change = [(115 - 509) / 509] x 100
Subtract the new number by the original number
115 - 509 = -394
-394 ÷ 509 = -0.7740667976424361
-0.7740667976424361 x 100 = -77.41%