-86.8% is the change from 644 to 85
Calculation steps:
[( 85 - 644 ) ÷ 644] x 100 = -86.8%
Formula
Percentage change = [(85 - 644) / 644] x 100
Subtract the new number by the original number
85 - 644 = -559
-559 ÷ 644 = -0.8680124223602484
-0.8680124223602484 x 100 = -86.8%