-74.7% is the change from 83 to 21
Calculation steps:
[( 21 - 83 ) ÷ 83] x 100 = -74.7%
Formula
Percentage change = [(21 - 83) / 83] x 100
Subtract the new number by the original number
21 - 83 = -62
-62 ÷ 83 = -0.7469879518072289
-0.7469879518072289 x 100 = -74.7%