-96.57% is the change from 612 to 21
Calculation steps:
[( 21 - 612 ) ÷ 612] x 100 = -96.57%
Formula
Percentage change = [(21 - 612) / 612] x 100
Subtract the new number by the original number
21 - 612 = -591
-591 ÷ 612 = -0.9656862745098039
-0.9656862745098039 x 100 = -96.57%