-19.61% is the change from 668 to 537
Calculation steps:
[( 537 - 668 ) ÷ 668] x 100 = -19.61%
Formula
Percentage change = [(537 - 668) / 668] x 100
Subtract the new number by the original number
537 - 668 = -131
-131 ÷ 668 = -0.19610778443113772
-0.19610778443113772 x 100 = -19.61%