-7.53% is the change from 691 to 639
Calculation steps:
[( 639 - 691 ) ÷ 691] x 100 = -7.53%
Formula
Percentage change = [(639 - 691) / 691] x 100
Subtract the new number by the original number
639 - 691 = -52
-52 ÷ 691 = -0.07525325615050651
-0.07525325615050651 x 100 = -7.53%