-19.67% is the change from 671 to 539
Calculation steps:
[( 539 - 671 ) ÷ 671] x 100 = -19.67%
Formula
Percentage change = [(539 - 671) / 671] x 100
Subtract the new number by the original number
539 - 671 = -132
-132 ÷ 671 = -0.19672131147540983
-0.19672131147540983 x 100 = -19.67%