-19.52% is the change from 671 to 540
Calculation steps:
[( 540 - 671 ) ÷ 671] x 100 = -19.52%
Formula
Percentage change = [(540 - 671) / 671] x 100
Subtract the new number by the original number
540 - 671 = -131
-131 ÷ 671 = -0.19523099850968703
-0.19523099850968703 x 100 = -19.52%