-78.7% is the change from 399 to 85
Calculation steps:
[( 85 - 399 ) ÷ 399] x 100 = -78.7%
Formula
Percentage change = [(85 - 399) / 399] x 100
Subtract the new number by the original number
85 - 399 = -314
-314 ÷ 399 = -0.7869674185463659
-0.7869674185463659 x 100 = -78.7%