-90.36% is the change from 685 to 66
Calculation steps:
[( 66 - 685 ) ÷ 685] x 100 = -90.36%
Formula
Percentage change = [(66 - 685) / 685] x 100
Subtract the new number by the original number
66 - 685 = -619
-619 ÷ 685 = -0.9036496350364963
-0.9036496350364963 x 100 = -90.36%