-29.97% is the change from 911 to 638
Calculation steps:
[( 638 - 911 ) ÷ 911] x 100 = -29.97%
Formula
Percentage change = [(638 - 911) / 911] x 100
Subtract the new number by the original number
638 - 911 = -273
-273 ÷ 911 = -0.2996706915477497
-0.2996706915477497 x 100 = -29.97%