-39.35% is the change from 991 to 601
Calculation steps:
[( 601 - 991 ) ÷ 991] x 100 = -39.35%
Formula
Percentage change = [(601 - 991) / 991] x 100
Subtract the new number by the original number
601 - 991 = -390
-390 ÷ 991 = -0.39354187689202824
-0.39354187689202824 x 100 = -39.35%