-98.8% is the change from 669 to 8
Calculation steps:
[( 8 - 669 ) ÷ 669] x 100 = -98.8%
Formula
Percentage change = [(8 - 669) / 669] x 100
Subtract the new number by the original number
8 - 669 = -661
-661 ÷ 669 = -0.9880418535127056
-0.9880418535127056 x 100 = -98.8%