-90.13% is the change from 669 to 66
Calculation steps:
[( 66 - 669 ) ÷ 669] x 100 = -90.13%
Formula
Percentage change = [(66 - 669) / 669] x 100
Subtract the new number by the original number
66 - 669 = -603
-603 ÷ 669 = -0.9013452914798207
-0.9013452914798207 x 100 = -90.13%