-57.79% is the change from 815 to 344
Calculation steps:
[( 344 - 815 ) ÷ 815] x 100 = -57.79%
Formula
Percentage change = [(344 - 815) / 815] x 100
Subtract the new number by the original number
344 - 815 = -471
-471 ÷ 815 = -0.5779141104294478
-0.5779141104294478 x 100 = -57.79%