-6.45% is the change from 930 to 870
Calculation steps:
[( 870 - 930 ) ÷ 930] x 100 = -6.45%
Formula
Percentage change = [(870 - 930) / 930] x 100
Subtract the new number by the original number
870 - 930 = -60
-60 ÷ 930 = -0.06451612903225806
-0.06451612903225806 x 100 = -6.45%