-39.09% is the change from 839 to 511
Calculation steps:
[( 511 - 839 ) ÷ 839] x 100 = -39.09%
Formula
Percentage change = [(511 - 839) / 839] x 100
Subtract the new number by the original number
511 - 839 = -328
-328 ÷ 839 = -0.3909415971394517
-0.3909415971394517 x 100 = -39.09%