-19.17% is the change from 824 to 666
Calculation steps:
[( 666 - 824 ) ÷ 824] x 100 = -19.17%
Formula
Percentage change = [(666 - 824) / 824] x 100
Subtract the new number by the original number
666 - 824 = -158
-158 ÷ 824 = -0.19174757281553398
-0.19174757281553398 x 100 = -19.17%