-5.43% is the change from 920 to 870
Calculation steps:
[( 870 - 920 ) ÷ 920] x 100 = -5.43%
Formula
Percentage change = [(870 - 920) / 920] x 100
Subtract the new number by the original number
870 - 920 = -50
-50 ÷ 920 = -0.05434782608695652
-0.05434782608695652 x 100 = -5.43%