-97% is the change from 999 to 30
Calculation steps:
[( 30 - 999 ) ÷ 999] x 100 = -97%
Formula
Percentage change = [(30 - 999) / 999] x 100
Subtract the new number by the original number
30 - 999 = -969
-969 ÷ 999 = -0.96996996996997
-0.96996996996997 x 100 = -97%