-78.91% is the change from 811 to 171
Calculation steps:
[( 171 - 811 ) ÷ 811] x 100 = -78.91%
Formula
Percentage change = [(171 - 811) / 811] x 100
Subtract the new number by the original number
171 - 811 = -640
-640 ÷ 811 = -0.7891491985203453
-0.7891491985203453 x 100 = -78.91%