-10% is the change from 690 to 621
Calculation steps:
[( 621 - 690 ) ÷ 690] x 100 = -10%
Formula
Percentage change = [(621 - 690) / 690] x 100
Subtract the new number by the original number
621 - 690 = -69
-69 ÷ 690 = -0.1
-0.1 x 100 = -10%
Example