-51.17% is the change from 815 to 398
Calculation steps:
[( 398 - 815 ) ÷ 815] x 100 = -51.17%
Formula
Percentage change = [(398 - 815) / 815] x 100
Subtract the new number by the original number
398 - 815 = -417
-417 ÷ 815 = -0.5116564417177915
-0.5116564417177915 x 100 = -51.17%