-7.06% is the change from 991 to 921
Calculation steps:
[( 921 - 991 ) ÷ 991] x 100 = -7.06%
Formula
Percentage change = [(921 - 991) / 991] x 100
Subtract the new number by the original number
921 - 991 = -70
-70 ÷ 991 = -0.07063572149344097
-0.07063572149344097 x 100 = -7.06%