-75.87% is the change from 866 to 209
Calculation steps:
[( 209 - 866 ) ÷ 866] x 100 = -75.87%
Formula
Percentage change = [(209 - 866) / 866] x 100
Subtract the new number by the original number
209 - 866 = -657
-657 ÷ 866 = -0.7586605080831409
-0.7586605080831409 x 100 = -75.87%