-2.21% is the change from 408 to 399
Calculation steps:
[( 399 - 408 ) ÷ 408] x 100 = -2.21%
Formula
Percentage change = [(399 - 408) / 408] x 100
Subtract the new number by the original number
399 - 408 = -9
-9 ÷ 408 = -0.022058823529411766
-0.022058823529411766 x 100 = -2.21%