-33.61% is the change from 961 to 638
Calculation steps:
[( 638 - 961 ) ÷ 961] x 100 = -33.61%
Formula
Percentage change = [(638 - 961) / 961] x 100
Subtract the new number by the original number
638 - 961 = -323
-323 ÷ 961 = -0.33610822060353795
-0.33610822060353795 x 100 = -33.61%