-17.78% is the change from 776 to 638
Calculation steps:
[( 638 - 776 ) ÷ 776] x 100 = -17.78%
Formula
Percentage change = [(638 - 776) / 776] x 100
Subtract the new number by the original number
638 - 776 = -138
-138 ÷ 776 = -0.17783505154639176
-0.17783505154639176 x 100 = -17.78%