-83.37% is the change from 511 to 85
Calculation steps:
[( 85 - 511 ) ÷ 511] x 100 = -83.37%
Formula
Percentage change = [(85 - 511) / 511] x 100
Subtract the new number by the original number
85 - 511 = -426
-426 ÷ 511 = -0.8336594911937377
-0.8336594911937377 x 100 = -83.37%