-22.44% is the change from 820 to 636
Calculation steps:
[( 636 - 820 ) ÷ 820] x 100 = -22.44%
Formula
Percentage change = [(636 - 820) / 820] x 100
Subtract the new number by the original number
636 - 820 = -184
-184 ÷ 820 = -0.22439024390243903
-0.22439024390243903 x 100 = -22.44%