-97.4% is the change from 807 to 21
Calculation steps:
[( 21 - 807 ) ÷ 807] x 100 = -97.4%
Formula
Percentage change = [(21 - 807) / 807] x 100
Subtract the new number by the original number
21 - 807 = -786
-786 ÷ 807 = -0.9739776951672863
-0.9739776951672863 x 100 = -97.4%