-15.71% is the change from 815 to 687
Calculation steps:
[( 687 - 815 ) ÷ 815] x 100 = -15.71%
Formula
Percentage change = [(687 - 815) / 815] x 100
Subtract the new number by the original number
687 - 815 = -128
-128 ÷ 815 = -0.1570552147239264
-0.1570552147239264 x 100 = -15.71%