-96.56% is the change from 611 to 21
Calculation steps:
[( 21 - 611 ) ÷ 611] x 100 = -96.56%
Formula
Percentage change = [(21 - 611) / 611] x 100
Subtract the new number by the original number
21 - 611 = -590
-590 ÷ 611 = -0.9656301145662848
-0.9656301145662848 x 100 = -96.56%