-79.9% is the change from 771 to 155
Calculation steps:
[( 155 - 771 ) ÷ 771] x 100 = -79.9%
Formula
Percentage change = [(155 - 771) / 771] x 100
Subtract the new number by the original number
155 - 771 = -616
-616 ÷ 771 = -0.7989623865110247
-0.7989623865110247 x 100 = -79.9%