-91.95% is the change from 870 to 70
Calculation steps:
[( 70 - 870 ) ÷ 870] x 100 = -91.95%
Formula
Percentage change = [(70 - 870) / 870] x 100
Subtract the new number by the original number
70 - 870 = -800
-800 ÷ 870 = -0.9195402298850575
-0.9195402298850575 x 100 = -91.95%