-89.52% is the change from 830 to 87
Calculation steps:
[( 87 - 830 ) ÷ 830] x 100 = -89.52%
Formula
Percentage change = [(87 - 830) / 830] x 100
Subtract the new number by the original number
87 - 830 = -743
-743 ÷ 830 = -0.8951807228915662
-0.8951807228915662 x 100 = -89.52%