-96.85% is the change from 667 to 21
Calculation steps:
[( 21 - 667 ) ÷ 667] x 100 = -96.85%
Formula
Percentage change = [(21 - 667) / 667] x 100
Subtract the new number by the original number
21 - 667 = -646
-646 ÷ 667 = -0.9685157421289355
-0.9685157421289355 x 100 = -96.85%