-23.72% is the change from 666 to 508
Calculation steps:
[( 508 - 666 ) ÷ 666] x 100 = -23.72%
Formula
Percentage change = [(508 - 666) / 666] x 100
Subtract the new number by the original number
508 - 666 = -158
-158 ÷ 666 = -0.23723723723723725
-0.23723723723723725 x 100 = -23.72%