-31.38% is the change from 991 to 680
Calculation steps:
[( 680 - 991 ) ÷ 991] x 100 = -31.38%
Formula
Percentage change = [(680 - 991) / 991] x 100
Subtract the new number by the original number
680 - 991 = -311
-311 ÷ 991 = -0.313824419778002
-0.313824419778002 x 100 = -31.38%