-15.34% is the change from 991 to 839
Calculation steps:
[( 839 - 991 ) ÷ 991] x 100 = -15.34%
Formula
Percentage change = [(839 - 991) / 991] x 100
Subtract the new number by the original number
839 - 991 = -152
-152 ÷ 991 = -0.15338042381432895
-0.15338042381432895 x 100 = -15.34%