-21.48% is the change from 810 to 636
Calculation steps:
[( 636 - 810 ) ÷ 810] x 100 = -21.48%
Formula
Percentage change = [(636 - 810) / 810] x 100
Subtract the new number by the original number
636 - 810 = -174
-174 ÷ 810 = -0.21481481481481482
-0.21481481481481482 x 100 = -21.48%