-7.91% is the change from 721 to 664
Calculation steps:
[( 664 - 721 ) ÷ 721] x 100 = -7.91%
Formula
Percentage change = [(664 - 721) / 721] x 100
Subtract the new number by the original number
664 - 721 = -57
-57 ÷ 721 = -0.07905686546463246
-0.07905686546463246 x 100 = -7.91%