-2.39% is the change from 837 to 817
Calculation steps:
[( 817 - 837 ) ÷ 837] x 100 = -2.39%
Formula
Percentage change = [(817 - 837) / 837] x 100
Subtract the new number by the original number
817 - 837 = -20
-20 ÷ 837 = -0.023894862604540025
-0.023894862604540025 x 100 = -2.39%