-33.7% is the change from 991 to 657
Calculation steps:
[( 657 - 991 ) ÷ 991] x 100 = -33.7%
Formula
Percentage change = [(657 - 991) / 991] x 100
Subtract the new number by the original number
657 - 991 = -334
-334 ÷ 991 = -0.33703329969727547
-0.33703329969727547 x 100 = -33.7%