-21.29% is the change from 991 to 780
Calculation steps:
[( 780 - 991 ) ÷ 991] x 100 = -21.29%
Formula
Percentage change = [(780 - 991) / 991] x 100
Subtract the new number by the original number
780 - 991 = -211
-211 ÷ 991 = -0.2129162462159435
-0.2129162462159435 x 100 = -21.29%