-83.17% is the change from 921 to 155
Calculation steps:
[( 155 - 921 ) ÷ 921] x 100 = -83.17%
Formula
Percentage change = [(155 - 921) / 921] x 100
Subtract the new number by the original number
155 - 921 = -766
-766 ÷ 921 = -0.8317046688382194
-0.8317046688382194 x 100 = -83.17%