-96.63% is the change from 623 to 21
Calculation steps:
[( 21 - 623 ) ÷ 623] x 100 = -96.63%
Formula
Percentage change = [(21 - 623) / 623] x 100
Subtract the new number by the original number
21 - 623 = -602
-602 ÷ 623 = -0.9662921348314607
-0.9662921348314607 x 100 = -96.63%