-80.73% is the change from 109 to 21
Calculation steps:
[( 21 - 109 ) ÷ 109] x 100 = -80.73%
Formula
Percentage change = [(21 - 109) / 109] x 100
Subtract the new number by the original number
21 - 109 = -88
-88 ÷ 109 = -0.8073394495412844
-0.8073394495412844 x 100 = -80.73%