-80.78% is the change from 515 to 99
Calculation steps:
[( 99 - 515 ) ÷ 515] x 100 = -80.78%
Formula
Percentage change = [(99 - 515) / 515] x 100
Subtract the new number by the original number
99 - 515 = -416
-416 ÷ 515 = -0.8077669902912621
-0.8077669902912621 x 100 = -80.78%