-21.23% is the change from 391 to 308
Calculation steps:
[( 308 - 391 ) ÷ 391] x 100 = -21.23%
Formula
Percentage change = [(308 - 391) / 391] x 100
Subtract the new number by the original number
308 - 391 = -83
-83 ÷ 391 = -0.21227621483375958
-0.21227621483375958 x 100 = -21.23%