-21.36% is the change from 810 to 637
Calculation steps:
[( 637 - 810 ) ÷ 810] x 100 = -21.36%
Formula
Percentage change = [(637 - 810) / 810] x 100
Subtract the new number by the original number
637 - 810 = -173
-173 ÷ 810 = -0.21358024691358024
-0.21358024691358024 x 100 = -21.36%