-23.87% is the change from 666 to 507
Calculation steps:
[( 507 - 666 ) ÷ 666] x 100 = -23.87%
Formula
Percentage change = [(507 - 666) / 666] x 100
Subtract the new number by the original number
507 - 666 = -159
-159 ÷ 666 = -0.23873873873873874
-0.23873873873873874 x 100 = -23.87%