-2.74% is the change from 840 to 817
Calculation steps:
[( 817 - 840 ) ÷ 840] x 100 = -2.74%
Formula
Percentage change = [(817 - 840) / 840] x 100
Subtract the new number by the original number
817 - 840 = -23
-23 ÷ 840 = -0.02738095238095238
-0.02738095238095238 x 100 = -2.74%