-18.16% is the change from 991 to 811
Calculation steps:
[( 811 - 991 ) ÷ 991] x 100 = -18.16%
Formula
Percentage change = [(811 - 991) / 991] x 100
Subtract the new number by the original number
811 - 991 = -180
-180 ÷ 991 = -0.18163471241170534
-0.18163471241170534 x 100 = -18.16%