-12.9% is the change from 1000 to 871
Calculation steps:
[( 871 - 1000 ) ÷ 1000] x 100 = -12.9%
Formula
Percentage change = [(871 - 1000) / 1000] x 100
Subtract the new number by the original number
871 - 1000 = -129
-129 ÷ 1000 = -0.129
-0.129 x 100 = -12.9%