-17.87% is the change from 817 to 671
Calculation steps:
[( 671 - 817 ) ÷ 817] x 100 = -17.87%
Formula
Percentage change = [(671 - 817) / 817] x 100
Subtract the new number by the original number
671 - 817 = -146
-146 ÷ 817 = -0.17870257037943696
-0.17870257037943696 x 100 = -17.87%