-34.53% is the change from 976 to 639
Calculation steps:
[( 639 - 976 ) ÷ 976] x 100 = -34.53%
Formula
Percentage change = [(639 - 976) / 976] x 100
Subtract the new number by the original number
639 - 976 = -337
-337 ÷ 976 = -0.3452868852459016
-0.3452868852459016 x 100 = -34.53%