-2.86% is the change from 839 to 815
Calculation steps:
[( 815 - 839 ) ÷ 839] x 100 = -2.86%
Formula
Percentage change = [(815 - 839) / 839] x 100
Subtract the new number by the original number
815 - 839 = -24
-24 ÷ 839 = -0.028605482717520857
-0.028605482717520857 x 100 = -2.86%